After examining the evidence at a site, a geologist thinks that a river could have once flowed through the area. what evidence would support this conclusion? a) the site is a vast, open grassland. b) a high level of tectonic activity is present. c) this location contains igneous rocks everywhere. d) many sedimentary rocks with fossils have been found.

The presence of many sedimentary rocks with fossils acts as evidence to prove the existence of a flowing river in the region.

Explanation:

Rivers carry a lot of debris along with them. These include rocks, sand and fossil remains of the organic matter that got mixed with the river water in some or the other way. In its usual course, the river carries and dumps these rocks and fossils every now and then. Thus the presence of sedimentary rocks and fossils in a region is partially evident of the existence of a river in the region.

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.