The correct option is
A Garden pea
Mendel's work on genetics was mainly concentrated on
Pisum sativum, otherwise known as garden pea plant. He took 7 characters into consideration. The characters chosen were:
1. Flower colour - purple or white
2. Flower position - axial or terminal
3. Stem length - long or short
4. Pod shape - inflated or constricted
5. Pod colour - yellow or green
6. Seed shape - round or wrinkled
7. Seed colour - yellow or green
So, the correct answer is option A.