The correct option is C chromosomes
Mendel performed hybridisation experiments on garden pea plants for seven years.
In hybridisation experiments, Mendel crossed pea plants that differed in characters and obtained hybrids (F1 generation) which on selfing produced the F2 generation. Later he analysed the results.
Mendel was the first scientist to apply statistical analysis and mathematical logic to problems in biology which was unacceptable to biologists of that time.
After conducting experiments, he came up with the laws of inheritance.
Mendel proposed that there are discrete units called factors (now called genes) that have information for the expression of the traits. But he had no idea of the physical nature of those factors and neither he had an idea of chromosomes.
Later Sutton and Boveri stated that chromosomes carry genes (factors) at specific locations and this was proved by Morgan.