Why do the Spanish adventurers call the estuary near eir campsite the "Bay of Horses"?
A There are several herds of horses nearby.
B The surrounding land is shaped like a horse's head.
C They are killing, roasting, and eating their horses.
D The expedition's leader raises and sells horses.

C.

Explanation:

The campers called the estuary near their campsite 'Bay of Horses' because every third day they used kill a horse, roast it and eat it. This record of Spanish adventurers is found in the journal ny Cabeza De Vaca. In the Fall of 1528 he wrote an entry describing the situation of Spanish Campsite.

He described that 250 hungry Spanish named estuary near their campsite 'Bay of Horses' because they began to kill their own horses, roast them, and eat them. After people landed on the Florida coast on Vaca's command, and without finding any gold, being separated from ship, and lack of food they began to consume their own horses for the sake of survival.

Thus option C is correct.