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?

    D: illusory correlation

    Incorrect.
Illusory correlation is a tendency to sometimes see two things as related to each other, when no real relation exists.  Examples of illusory correlation are found in superstitions.  For example, some people believe that breaking a mirror brings seven years of bad luck.