WHICH SENTENCE IS INCORRECT

5. - KIEM TRA 1 TIET SO 1
KIEM TRA 1 TIET SO 1
5. Which sentence is INCORRECT?A. You can attract your friend's attention at a noisy party by waving.B. You can attract the waiter's attention in a restaurant by whistling.C. Pointing at someone is usually considered impolite.D. At the airport, big, obvious non-verbal signals are appropriate.