Change into indirect speech: The officer said to the soldiers, "March to the field immediately."
Correct: B
Imperative sentences are reported using reporting verbs like 'ordered', 'commanded', 'requested', etc., followed by 'to + verb'. 'March' becomes 'to march'. 'Immediately' can change to 'at once' or remain, but 'at once' is more appropriate in indirect speech. The correct answer is: The officer ordered the soldiers to march to the field at once.