Final answer:
Avery is worried about the decreased effectiveness of pharmaceutical samples due to changes in air pressure during transportation. Hence the correct answer is option A
Step-by-step explanation:
Avery's concern about taking pharmaceutical samples on a plane is related to the potential impact of air pressure on their quality. Specifically, Avery is worried about the potential decreased effectiveness of the samples due to changes in air pressure during transportation.
Hence the correct answer is option A