Carbon is the only element that can form so many different compounds because each carbon atom can form four chemical bonds to other atoms, and because the carbon atom is just the right, small size to fit in comfortably as parts of very large molecules.
<span>Notice a couple of things
different between (A) and (B). It was NOT the first time a biologist
proposed that species changed through time (so it's not B). But it
finally *solidified* that idea by giving "change through time"
(evolution) a MECHANISM. It gave a plausible explanation for WHY
species change over time, in a testable way that made sense and had
evidence to support it.
So it finally dismissed the idea that species are constant.
It also emphasized that the simple presence of *variation* within a population was a key reason for evolution.
While we're at it ... (C) is wrong because it's not *individuals* that
acclimate (adapt) to their environment, but the population (the species)
as a whole.
And (D) is wrong because it had nothing to do with economics or the monarchy.</span>