The correct answer is A. The teacher asked Reema why she can’t come to school on time.
The teacher is asking Reema a question, and the question is “Why can’t you come to school on time?” This means that the teacher is asking Reema for a reason why she is not able to come to school on time. The teacher is not asking Reema if she can’t come to school on time, or if she couldn’t come to school on time. The teacher is asking Reema why she is not able to come to school on time.
Option B is incorrect because the teacher is not asking Reema if she can’t come to school on time. The teacher is asking Reema why she is not able to come to school on time.
Option C is incorrect because the teacher is not asking Reema why she couldn’t come to school on time. The teacher is asking Reema why she is not able to come to school on time.
Option D is incorrect because the teacher is not asking Reema why she couldn’t come to school on time. The teacher is asking Reema why she is not able to come to school on time.