Alright! Your being asked to rank a group by there taxonomy. You can remember this for a test by using "Dear King Phillip Came Over for Good Soup" or domain, kingdom, phylum, class, order, family, genus, species. So rank them from least to most specific. See you if you can figure it out with that!
A: black spots are dominant
B: ss
C: both parents must be heterozygous to produce an offspring that expresses the recessive trait.
D: SS, Ss, and ss
Hope this helps!