Early settlers had to choose a location that would meet their most basic needs. Therefore, the early settlers of Mesopotamia, Egypt, India, China, and Rome all settled near

They would need food and water so if they settled by a river or coastline they would have access to both food and water plus they could irrigate their crops from the water source

I hope this helps in some way

The sun's parallax would be 180 degrees, greater than which you can't get.  so a. would be your anwser 

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast.