What is a base?
a. a substance that can donate an h+ ion

b. a substance that has a low ph value

c. a substance that is alkaline

d.a substance that can accept an oh– ion

C. a substance that is alkaline

Explanation:

Alkaline substances are basic substances. Like all basic substances, alkaline substances have a high pH, above 7, in addition to mandatory release of the OH- anion in aqueous solutions.

Accordingly, we can say that it is incorrect to say that the bases can release the H + cation, or that it is a substance that has a low pH, or that it is a substance that receives the H + cation.

An organisms niche is (A) The range of physical and biological conditions in which an organism lives and the way in which it uses those conditions.
 Technically, any of the answers could be true, however, A is the only one that offers a broad definition.A niche is not only the location and conditions in which an organism lives, but also the organisms role within that niche and how it uses the resources to survive.