When marine organisms are present in a rock, it indicates that:

marine organisms moved to land.

the rock is very old.

the rock has moved.

the rock was once in a marine environment.

D. The rock was once in a marine environment.

Explanation:

The question says when MARINE organisms are present in a rock, meaning it was in a marine environment. Most fossils are found on land, but scientists can easily figure out of it was originally from land or marine based.  

6 units. ab and lo are congruent sides, and if ab= 6 units, then lo would be the same.

necessary and proper clause. the congress shall have power to all laws which shall be necessary and proper for carrying into execution the foregoing powers, and all other powers vested by this constitution in the government of the united states, or in any department or officer thereof.