B . Excessive commercial fishing
Reason: the other options are good things this is the only bad thing
Trui belive the answer is true if not I am very sorry but I recall one of my teachers mentioning something like that...I hope this helped
Answer:
The pollen grain is creating a tube down the style of the flower. <u>It is necessary as that is how the pollen is able to travel down the style into the ovary where the baby seed is located. This is how the seed is fertilized, and is ready for reproduction.</u>