Question

9 what does a stratigraphist study?
a dinosaurs
b time
c rock layers
d the formation of the earth

Explanation:

A stratigrapher studies rock layers (stratigraphy focuses on rock strata, their deposition, age relationships, etc.). Dinosaurs are studied by paleontologists, time in broader geological time scales is part of geochronology, and Earth's formation is studied by planetary scientists/geologists in a broader sense, but stratigraphy specifically deals with rock layers.

Answer:

C. Rock layers