Answer: c. signal amplification
Explanation:
The uncoupling of the G-protein and inhibiting of the signal amplification are the two affects of the pertusis toxin. It is released by the bacteria called Bordetella pertusis. The G-proteins are affected by the action of pertusis toxin. The production to the excess level of cAMP due to the conversion of ATP into cAMP the ribosylation of the ADP molecules occurs due to pertusis toxin. This leads to the damage of G-proteins.