Question

how do organisms form carbon films?
organisms turn into rock.
residue is left on rocks when organisms decay.
hollow forms are left in sediment by decaying organisms.
organisms leave evidence of their activities, such as footprints.

Explanation:

Carbon films are formed when an organism decays. During this process, the organic material (except for carbon) is lost, and a thin layer of carbon residue is left on the rock.

• Option 1: Organisms turning into rock is not the process of forming carbon films.
• Option 3: Hollow forms left in sediment by decaying organisms describe molds, not carbon films.
• Option 4: Evidence of activities like footprints are trace fossils, not carbon - film formation.

Answer:

Residue is left on rocks when organisms decay.