Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms, and because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules. ... They can even join "head-to-tail" to make rings of carbon atoms.
Answer: a.Camouflage
Simulation is a deception in the characteristics of the organism which favors it's survival in the environment. Camouflage is a kind of simulation, in which the organism adapt the color or shape according to the surrounding environment in order to remain undetected by a prey and a predator. For example, chameleon is a reptile, which can change it's color according to the surrounding environment. It changes it's color to green in grass and remains brown in the tree bark in order to eat insects and remain undetected from prey and predator population.
Therefore, According to the simulation, camouflage helps predators to survive by allowing them to sneak up on their prey.
Skin. hair. nails. hope these helped!