If a paid keyword has an Assisted/Last Click or Direct Conversions value of .5, which of the following is true?

If a paid keyword has an Assisted/Last Click or Direct Conversions value of .5, which of the following is true?
  A)  The keyword played an assist role in exactly one conversion
  B)  The keyword played an assist role less often that it played a last click role
  C)  The keyword played an assist role in exactly five conversions
  D)  none of these answers