Greg found a rock with seashells and sand in it. What process likely caused this rock to form? a
from layers of sediment that were cemented together
b
from rocks mixing with sea water
c
from heat and pressure below the suface of Earth
d
from melted rock that cooled above th surface

Its A

Explanation: use the process of discarding. Ita not d because That would be igneous rocks, its not c because that would be metamorphic rocks, its clear that its not b because that just doesnt make any sense, so that just leaves A.  btw u can trust me because i got this question in a test and it was marked correct.

the anwser is missions