Question

question 3
what evidence found in the summit rock led geologists to its possible origin?
the size of the crystalsthe size of the sediments that comprise the rockthe presence of crinoid fossils in the rockits chemical composition

Explanation:

Crinoid fossils are marine invertebrates. Their presence in rock indicates that the rock was formed in a marine environment. This helps geologists determine the rock's origin.

Answer:

the presence of crinoid fossils in the rock