Organisms well suited to their environment:
select one:
a. are always larger than organisms less suited to that environment.
b. reproduce more successfully than organisms who are less suited for the same environment.
c. need less food than organisms less suited to that environment.
d. always live longer than organisms less suited to that environment.

Reproduce more successfully than organisms who are less suited for the same environment.

Explanation:

If they are well suited they don't necessarily have to be too big or too small small.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds