Answer:
Option D, ST, St, sT, st
Step-by-step explanation:
Genotype of corn plant is SsTt
If we are required to determine the genetic combinations that could be present in a single grain of pollen produced by the plant would be equivalent to the cross between the two traits i.e
Ss x Tt
The resulting genetic combinations would be a pair of allele having one allele of each trait.
Hence, the possible genetic combinations are -
ST, St, sT, st
Hence, option D is correct