The answer is 3.
The structure A is the oviduct, where fertilization usually takes place. If the both the oviducts are blocked, the eggs could still be produced in the ovaries. So 1 is incorrect.
For 2, sperm is produced in male and insulin is related to the pancreas, not the uterus. So, incorrect.
For 3, the sperms could not travel to the oviduct and meet with the egg. Thus, no fertilization.
For 4, if there is no fertilization, embryos could never develop.
