The correct option is B Segregation
3:1 ratio was the important clue for Mendle to crack the law of inheritance. When he crossed the two pea plants in a scientific manner, the result obtained were in the ratio of 3:1 and he concluded that individual has two copies of a given gene that determines the trait of the offspring. He gave the law of segregation i.e., one of the two gene copies present in the individual is passed on to the gametes. Thus, the correct answer is option B.