2: Why is it easier to think of words that start with the letter K than
  words that have the letter K as the third letter?

    C: false consensus bias

    Incorrect.
The false consensus bias is a mechanism by which people tend to enhance their self-images by overestimating the degree to which others agree with their opinions (e.g., everybody wants democracy) and practice their undesirable behaviors  (everybody cheats on his income taxes).