I think the answer is b not too sure though
When testing a hypothesis, scientists use repeated trials and replication to make sure that they get the same answer each time, and that it isn't just a lucky guess the first time. They need be sure that the answer to their hypothesis is 100% the same every time.
The muscle tissue that can be consciously controlled is
skeletal
Inertia. The reason why is because of Newton's First Law Of Motion, when you let go of the cart when you push on it, it will continue to roll until gravity, friction, and wind resistance eventually stops the cart.
The cells increase without an increase in size
Single felled zygotes divide into smaller and smaller cells