The statement that is the most true regarding the states of matter is the first statement.
A. Most matter on Earth exists as a solid, liquid, or gas.
This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.
Therefore, B is incorrect.
C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.
D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.