The sentence is given in direct speech is in interrogative form, The reporting verb is in past tense and therefore the reported speech will change according to the rules. Reporting verb “said” will change to“asked”. The reported speech is in simple present tense which will change to past perfect tense in the indirect speech. the sentence in indirect speech will be ‘Rahul asked his teacher what the way to solve the question was?’ Thus, option A is the correct answer.