A coefficient of coincidence of 0.25 means that:____.
a. The frequency of double crossovers is 1/4.
b. The frequency of double crossovers is 1/4 of the number expected if there were no interference.
c. There were four times as many single crossovers as double crossovers.
d. There were four times as many single crossovers in one region as there were in an adjacent region.
e. There were four times as many parental as recombinant progeny.