The correct answer is A. Mr. Rao told the Station Master that he had to go into the town that day.
The sentence “I have to go into the town today”, Mr. Rao said to the Station Master. is a direct quote. In a direct quote, the speaker’s exact words are used. In this case, Mr. Rao is the speaker and the Station Master is the listener. Mr. Rao is telling the Station Master that he has to go into the town that day.
Option B is incorrect because Mr. Rao is not advising the Station Master. He is telling him.
Option C is incorrect because Mr. Rao is not speaking to the Station Master. He is telling him.
Option D is incorrect because Mr. Rao is not telling the Station Master that he will go into the town that day. He is telling him that he has to go into the town that day.