First thing is Male gametes are called sperm and Female gametes are called eggs. So some physical differences are that the eggs are spherical in shape, much larger then sperm, and are immobile (they stay in the female reproductive organ during fertilization). Sperm are smaller, are in a cone shape, and have tails so the could move to the egg during fertilization.
They are all freshwater. So the closest would be c. an estuary since it has a free connection with the sea since the sea is not freshwater.
So C.
hope this helps!
Colder temperatures that last for a short period of time such as 3-4 days.
