The wording is very ackward but the logic is sound. Each means every in this case. All x are y. All x are z.
So A, B, C are true.
D is very badly worded but also logically true.
Proper English would be "Each square has round corners. All squares are red. A) There can be squares with red corners.... d) The squares are red with round corners. e) None of the above. "