Select the option that expresses the given sentence in reported speech.

Mother said, “Abhinav slipped while trying to board a bus.”

Mother said that Abhinav had slipped while trying to board a bus.

The correct option is: Mother said that Abhinav had slipped while trying to board a bus.

The other options are incorrect because they do not follow these rules:

• Mother told that Abhinav slipped while trying to board a bus. - This sentence does not change the present tense to the past tense for the reporting verb "told."
• Mother said that Abhinav slipped while trying to board a bus. - This sentence does not change the present tense to the past tense for the auxiliary verb "had."
• Mother says that Abhinav slipped while trying to board a bus. - This sentence uses the present tense for the reporting verb "says," which is incorrect in indirect speech.