What is a niche?

an organism’s living and nonliving interactions with its environment
an organism’s ability to interbreed with other organisms
an organism’s ability to reproduce asexually and produce organisms identical to itself

Option A, an organism’s living and nonliving interactions with its environment

Explanation:

The environment in which an organism habitat comprising of all its interaction with all biotic and abiotic factors is known as a niche. All organisms in an ecosystem acquire a niche which defines its role in the ecological system,  energy flow and recycling of nutrients. It also include the type of relationship an organism in an ecosystem have with all other organisms such as parasitic, mutualistic, etc.

Option A

a, i am pretty sure.