The correct type of food chain in this scenario is a detritus food chain. A detritus food chain starts with dead organic matter, such as the dead animal in this case. Decomposers, like maggots, break down the dead organic matter into simpler compounds. These decomposers are then consumed by other organisms, like the frog. The frog is then eaten by a snake, which is the final consumer in this food chain.

Let`s look at the other options to better understand why they are not the correct type:

1) Decomposer food chain: While decomposers are involved in this food chain, the term "decomposer food chain" generally refers to a food chain that consists solely of decomposers breaking down dead organic matter.

3) Grazing food chain: A grazing food chain starts with plants, which the primary consumers (herbivores) consume. This food chain does not involve dead organic matter.

4) Parasitic food chain: A parasitic food chain involves a parasite that lives on or within a host, obtaining nutrients from it. This food chain does not involve dead organic matter.