Correct Option: C

J. Hammerling (1934) conducted experiments using two species of green algae Acetabularia crenulata and A. mediterranea. They differ in the shapes of their caps. The nucleus in both species is situated in rhizoids at the bottom of stalk. After removing cap, if stalk of one species is grafted on rhizoid of the other species, shape of the cap will be determined by nucleus, not by the stalk. This experiment makes clear that the characters of an individual are controlled by nucleus.