Three little piggy's, what are you asking?
Although this is a subjective question, the best option for probably be "D like the sun and the interlopers" in terms of which two stories seem to have similar general themes.
The answer is letter a. The Olmec culture is recalled today in part because it was the first Mesoamerican culture to build small cities, most particularly San Lorenzo and La Venta. It was said there were an abundant rainfall and seasonal flooding within the site the Olmec Civilization in those places.
Hrothgar asked Beowulf to battle Grendel's mother because the king believed he was the only man capable of dealing with such monsters. This was because Beowulf had earlier succeeded in mortally wounding Grendel. Further, Hrothgar wanted revenge for his close friend.