The tet offensive was the turning point of the vietnam war and showed the military strength of north vietnam

Actually Tet was more of a political victory for the North.  They launched a surprise attack on South Vietnam during the Tet holiday on January 30, 1968.  They attacked not only military targets but towns and cities.  Communist forces managed to storm the U.S. Embassy.  Though a counterattack enabled the U.S. regain the territories assaulted by the North, the reaction at home was so negative that support for American involvement in the States dropped.  This led to the withdrawal of U.S. troops from Vietnam and eventually the North conquered the South.

i believe it d) heterogeneous