I've seen many conflicting answers online: For optical storage, does a pit represent a '1' bit or does a land represent a '1' bit?
C.  None of the above.

From Wikipedia:


  The frames of channel data are finally written to disc physically in the form of pits and lands, with each pit or land representing a series of zeroes, and with the transition points—the edge of each pit—representing 1.


A change from pit to land (or land to pit) is a 1.

Consecutive pits (or consecutive lands) is a 0.