The diagram illustrates a carpel following pollination. Pollen grains from two different species of flower have landed on the stigma. What accounts for the different germination of the two kinds of pollen grains shown?
- ACross-pollination is better than self-pollination.
- BAfter self-pollination, germination of pollen grains of species 2 is prevented.
- CThe carpel is from a flower of species 1.
- DThe carpel is from a flower of species 2.