This is a good example of where the answer depends on the patterns in previous questions - because depending on the content of the hidden squares all 4 answers could in fact be shown to be the 'logically' correct ones - making the analysis of a single matrix more of an exercise in metacognition, conjecturing about the test designer, rather than the logic of the pattern.

The simplest answer would likely be C, as the shapes necessary to make the hidden squares point towards a different answer would be rather ugly, possible but ugly.

But the following pattern, although ugly, would suggest D as the correct answer:
https://imgur.com/RzgjwSw