When there isn't enough room in the cell for two complete molecules of DNA, the prokaryote stops replication and undergoes cell division.
A sperm and egg combine to make a zygote. (or fertilized egg)
So, the answer would be "A".
I hope this helps!
~cupcake
i believe the answer u might be looking for is number 3. plants breathe carbon dioxide, so an increase in plant life could help aid world hunger.