After the fourth crusade, supporting among europeans for the crusades
grew even stronger
began to decline
stayed the same
collapsed

Began to decline

Explanation:

The Fourth Crusade (1202-1204) begun with the intention of taking the Holy Land, then in Muslim hands, through the conquest of Egypt. However, the crusade was diverted from its original purpose and the Crusaders, together with the Venetians, seized and sacked Constantinople, a Christian capital city of the Byzantine Empire.

Not achieving set goals was one of the reasons that the crusades started losing support.

The answer on eDgenUiity is:

B)  Began to decline

these civilizations were located around fertile rivers, where they could produce an abundance of crops