Round is a dominant characteristic. When crossing two heterozygotes, Rr x Rr, the dominant characteristic will be present in 3/4 of the offspring (being the offspring RR, Rr, Rr, rr), because dominant traits are expressed whenever there is a dominant allel (in this case, R) present.
Green is a recessive characteristic. When crossing two heterozygotes, Yy x Yy, the recessive characteristic will be present in 1/4 of the offspring (being the offspring YY, Yy, Yy, yy), because recessive traits only are expressed is homozygous pairs (rr).
Smooth is a dominant characteristic. It will happen the same as it happened with the Round characteristic. When crossing two heterozygotes, Cc x Cc, the dominant characteristic will be present in 3/4 of the offspring (being the offspring CC, Cc, Cc, cc), dominant traits are expressed whenever there is a dominant allel (in this case, C) present.
As the Principal of Independent Assortment states, different genes independently separates from one another, which means that the result would be a combination of the probabilities of each trait. Therefore, we must multiply the probabilities of having round pods with the chances of having green pods and small pods as well, as follows:
3/4 * 1/4 * 3/4 = 9/64
So, the correct answer is A. 9/64