Why was the tet offensive considered as surprise attack?

a. the north vietnamese were able to sneak up quietly on the tents of the americans.

b. because the northern vietnamese and vietcong were surprised by americans and south vietnamese using bows and arrows in battle.

c. the north vietnamese and the vietcong mounted a large attack on tet, the vietnamese new year holiday; a day when most didn't expect it.

d. because the vietcong attacked on christmas day

C) Tet Offensive was considered as surprise attack because the North Vietnamese and the Vietcong mounted a large attack on Tet, the Vietnamese New Year holiday; a day when most didn't expect it.  

It was a surprise that shook the American government leading to mistrust of the system by the natives. It created so much conflict that the ruling president then was not re-elected to power. Only after the attack did the people realize the magnitude of the battles had been underestimated or the presidency had previously hidden information about the enormity of the battle.  

The US and Vietnamese troops both suffered major losses while the US government was weakened and doubted by its peoples.  

the answer is title i subtitle b

d) iowa i believe is the answer