A bacterium that is exposed to a toxin in its environment can make an enzyme to neutralize the toxin. The bacterium controls protein synthesis to produce the enzyme by activating an inducible operon. The activation of the operon causes the transcription of the mRNA that codes for the enzyme. The mRNA is then translated to make the specific enzyme needed to neutralize the toxin.

What phenomenon is demonstrated in this example?

A
Evolution by natural selection
B
Cell differentiation by prokaryotes
C
Adaptation to external stimuli
D
Regulation of gene expression