The answer would be (C) i believe.
Protocells are self-organized, spherical collection of lipids. This is the proposed as the stepping stone to the origin life. One of the important qualities of protocells is its self-replicating, using the amphiphilic molecules. This requires repeatable set of chemical events.
Solution:
Two plants are crossed. One has the genotype Tt and the other has the genotype Tt. This means that both individuals are heterozygous.
According to this information, we obtain the following Punnett Square: