How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?

Correct option is B. Seven
Seven pairs of contrasting characters in pea plants were studied by Mendel in his experiments. They were : i) form of seed; ii) colour of cotyledons; iii) colour of seed coat; iv) form of pod; v) colour of pod; vi) position of flower; vii) height of plant (length of stem).