What are the guidelines to execute a missed approach during circling?
Flying a missed approach while circling can require some judgement, as the procedures are designed to originate at the missed approach point. Going missed while circling can mean starting the procedure some distance away from the MAP. The goal of the initial procedure should be to intercept the published missed approach course, while maintaining obstacle and traffic clearance. Put another way, a pilot may deviate from the letter of the procedure, if doing so follows the spirit of it.

In this situation, I would recommend option B. The procedure will provide obstacle clearance when started from three points: 443 MSL and about 4000 feet from the RW12 threshold (LPV minima); 638 MSL and about 11,500 feet from RW12 (LNAV/VNAV); and 600 MSL over the RW12 threshold (LNAV and circling). The procedure assumes you can climb at least 200 ft/nm, so to climb 100 feet would require less than 3035 feet across the ground. This puts you within the area where the published missed approach starts. Once you reach 700 feet, you can turn directly to the VOR and continue the procedure as published. The initial turn would normally be towards the landing runway, but in this example the runway is straight ahead.

If you descended below circling minima and needed a significant climb to get back, consider circling over the airport until either reaching 700 feet before flying towards the VOR.

The FAA has recommends the thought process above in the AIM, section 5-4-21. Emphasis mine:


  5-4-21 (c): If visual reference is lost while circling−to−land
  from an instrument approach, the missed approach
  specified for that particular procedure must be
  followed (unless an alternate missed approach
  procedure is specified by ATC). To become
  established on the prescribed missed approach
  course, the pilot should make an initial climbing turn
  toward the landing runway and continue the turn until
  established on the missed approach course. Inasmuch
  as the circling maneuver may be accomplished in
  more than one direction, different patterns will be
  required to become established on the prescribed
  missed approach course, depending on the aircraft
  position at the time visual reference is lost.
  Adherence to the procedure will help assure that an
  aircraft will remain laterally within the circling and
  missed approach obstruction clearance areas. Refer
  to paragraph h concerning vertical obstruction
  clearance when starting a missed approach at other
  than the MAP.  


[...]


  5-4-21 (h): ... In the event a balked (rejected) landing occurs at a position
  other than the published missed approach
  point, the pilot should contact ATC as soon as possible
  to obtain an amended clearance. If unable to
  contact ATC for any reason, the pilot should attempt
  to re−intercept a published segment of the missed approach
  and comply with route and altitude
  instructions. If unable to contact ATC, and in the pilot’s
  judgment it is no longer appropriate to fly the
  published missed approach procedure, then consider
  either maintaining visual conditions if practicable
  and reattempt a landing, or a circle−climb over the
  airport...


The AIM includes a diagram that demonstrates a pilot turning against the missed-approach instructions when that is the safer course. The missed approach requires a climbing right turn to the VOR; the pilot in the scenario on the right chooses to make a left turn as that allows the initial climb to take place over the airport.


Source: FAA AIM