Genetic variation is the difference in the DNA sequences of individuals in a population. Genetic recombination is the main reason for the diversity of organism on earth.
The genetic variation takes place during gamete formation by recombination of DNA sequences which takes place during prophase of meiosis I.
Since genetic variation involves changes in the coding segments of the DNA called genes which leads to mutations, therefore, flowering time does not influence the genetic variation and option-A is the correct answer