What evidence supports a scientist's conclusion that fossil B is older than fossil A? (4 points)

a
Fossil A and fossil B were both found at the same depth below Earth's surface.

b
Fossil B was found at a depth of 185 meters below Earth's surface, while fossil A was found at a depth of 50 meters below Earth's surface.

c
Fossil B was found at a depth of 50 meters below Earth's surface, while fossil A was found at a depth of 185 meters below Earth's surface.

d
Fossil A was found below Earth's surface, while fossil B was found at surface level.

Plz help need this fast!