River deltas are? 1, caused by the movement of tectonic plates.
2, areas of infertile, rock soil.
3, formed by erosion.
4, created by seafloor spreading.

2

Explanation:

I think that the answer is 2 because river deltas are formed when sediments are moved somewhere else in order to make the delta. So is there are areas of infertile rock soil it could be easily moved to make a delta

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.