Unknown Circuit Symbol
The bottom symbol in B is a fairly common symbol for a motor.

The other one seems to be an uncommon symbol for a generator. This page identifies it as a DC generator:

http://avstop.com/ac/apgeneral/basiccircuit.html

But this page says it's "AC power":

http://www.electronic-symbols.com/electric-electronic-symbols/electric-generator-symbols.htm

Both pages are missing the + and - signs. The presence of + and - signs and the overall context suggest it's meant as a DC generator, or (less likely) a generic voltage source.

Unfortunately, as my links show, there's not a lot of consistency in these kinds of symbols.