Mendel was successful in formulating the laws of inheritance whereas his predecessors were not because
Mendel was successful in formulating the laws of inheritance whereas his predecessors were not because of the following reasons.
He selected only pure breeding varieties of pea for his experiments.
He took one or two characters at one time while his predecessor often studied all the traits simultaneously.
He formulated theoretical explanations for interpreting his results.
He used statistical methods and law of probability for analyzing results, etc.,
So, the correct explanation is ‘He studied one clear-cut character at a time’.