Question

Volcanic rock has often been found early in the rock record but less frequently in later rock layers what does this suggest to scientists about early earth
volcanic activity was more common in the past than it is today

volcanic activity is the same today as it was early in earth's history

volcanic rock is easier to find

volcanic rock is more easily preserved than other kinds of rock

Answer 1

The fact that volcanic rock has often been found early in the rock record but less frequently in later rock layers suggest to scientists the following conclusion  about early earth: volcanic activity was more common in the past than it is today.
Besides volcanic activity in general, also huge volcanic eruptions were much more common than today.