C. Science is a process of observation and experimentation
The reason why it would be C is because it makes the most sense. Here are the reasons why it wouldn't be the others
A: while science does explain why some things happen, it does not have the absolute truth. There are times where science is wrong.
B: Not all questions can be answered by science. For example, how would you solve the question "do you like apples or oranges better" with science?
C: correct, because science uses the scientific method with observation then experimentation
D: Science is not unchanging, there are times where the first answers are wrong and they must be changed, or new findings are added
hope this helps you :)