In the following question, a sentence has been given in Direct/Indirect speech. Out of the four alternatives suggested, select the one which best expresses the same sentence in Indirect/Direct speech.
The trainee asked his boss, "Shall I email this letter again, Sir?"

A

The trainee asked his boss politely if he shall email that letter again.

B

The trainee asked his boss politely if he should email that letter again, sir.

C

The trainee asked his boss politely if he shall email that letter again, sir.

D

The trainee asked his boss politely if he should email that letter again.