not that hard of a question just need a little help

In a series of rock layers, a geologist finds fossils
of a lizard-like dinosaur and a fern-like tree in layers that are 1.0 m and 1.5 m deep. However, in a layer that is 2.0 m deep, he finds fossils of bony fish and shellfish.

Which explains his findings?

A.
The ancient sea dried up and became land.

B.
The ancient land area was invaded by a sea.

C.
An asteroid hit the area, causing the dinosaur to become extinct.

D.
The continent shifted to a polar region.

Question

not that hard of a question just need a little help

In a series of rock layers, a geologist finds fossils 
of a lizard-like dinosaur and a fern-like tree in layers that are 1.0 m and 1.5 m deep. However, in a layer that is 2.0 m deep, he finds fossils of bony fish and shellfish.
 
Which explains his findings?
 
 A.
The ancient sea dried up and became land.
 
 B.
The ancient land area was invaded by a sea.
 
 C.
An asteroid hit the area, causing the dinosaur to become extinct.
 
 D.
The continent shifted to a polar region.

ectophine · Answer

I believe it would be B. A is suggesting that the sea came after land, but if the dinosaur and fern fossils were higher than the fish fossils, that wouldn't make sense. Also, C and D don't make much sense either, leaving B!

anonymous · Answer

No. A is the correct answer. The ocean fossils are BELOW the land fossils, suggesting that before there was land, there was ocean (The farther down something is the older). The only logical response based on this fact is that an ancient sea dried up.

ectophine · Answer

Oh whoops meant A! Got the two mixed up!