If I had to guess it would be C metabolism
A sperm and egg combine to make a zygote. (or fertilized egg)
So, the answer would be "A".
I hope this helps!
~cupcake
Answer:
Atoms are the most reactive when they have a full outer energy level.
Explanation:
Atoms are the least reactive and most stable when their outermost electron shell is full.
Answer b is the best example
