Which of the following situations accurately describes a difference between a food chain and a food web?

a. a carnivore receives 10% of the energy from it's prey in a food web.
b. a carnivore eats both a rabbit and a mouse in a food web.
c. a rabbit eats grass in a food chain.
d. a rabbit receives 90% of the energy from the grass it eats in a food chain.

“A carnivore eats both a rabbit and a mouse in a food web” accurately describes a difference between a food chain and a food web.

A food chain is a series of events in which one organism eats another and obtains energy. An example could be a forest food-chain. The bear is the top of the food chain. The bear eats a coyote. The coyote ate the rabbit. The rabbit ate the grass. Since the grass can't technically eat anything, it's the bottom of the food chain and the food chain ends. 

A food web is a diagram showing the various different plants and animals in an ecosystem in relation to each other. It encompasses many consumers of each different level, acknowledging that one predator may eat several different kinds of prey, and that one kind of prey may be eaten by several kinds of predators. There are many food chains within a food web, and one creature is not necessarily at the top of the hierarchy. 

The correct answer between all the choices given is the second choice or letter B. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.