What is the biggest difference between an ecosystem and a community?

a) a community includes only one type of organism and an ecosystem includes many types.
b) an ecosystem includes only living organisms and a community includes both living and nonliving parts.
c) a community does not include nonliving parts and an ecosystem includes both living and nonliving parts.
d) an ecosystem includes only one type of organism and a community includes many types.

The main difference between a community and an ecosystem is that the ecosystem is defined as the result of what happens when a community of living organisms shares and interacts within their environment. What this means is that the ecosystem is a product of a specific community. There are several types of ecosystems, for example, a marine ecosystem, the rain forest ecosystem, the swamp ecosystem, and the desert ecosystem, just to name a few. 
Hope this helped. :)

They include lobsters and crabs