Because evolution itself is a very slow process. Having said that, the chance of having a continuum of various animals would mean that evolution would have progressed very fast. Because evolution is slow, different species establish themselves for different ecological niches and environments, this enables them to become better through time at a certain environment which then leads to eventual diversification in the number of species.
(C)theories can be used to predict the existence of as of yet unobserved things or phenomena
There are multiple factors that don't play a part in water movement. We need a list of possible options.
I do believe the answer is B
