Question

the site on the surface of an enzyme where a substrate binds is called the
multiple choice
binding site
active site
allosteric site
reactive site

Explanation:

In biology (a subfield of Natural Science), the site on an enzyme where the substrate binds is defined as the active site. The binding site is a more general term, allosteric site is for regulatory molecules, and reactive site is not the correct term for enzyme - substrate binding.

Answer:

B. active site (assuming the second option is labeled B, with the text "active site")