Active transport requires cellular energy from ATP

Steps:

• Define active transport as movement against concentration gradients using energy.
• Identify energy source: ATP from cellular respiration in mitochondria.
• Link oxygen to ATP production via oxidative phosphorylation.
• Evaluate options for energy dependence indicators.

Why B is correct:

• Active transport uses ATP generated by mitochondria through aerobic respiration, requiring oxygen supply.

Why the others are wrong:

• A describes facilitated diffusion, a passive process down gradients without energy.
• C indicates specificity common to enzymes and carriers, not unique to active transport.
• D shows location but doesn't imply energy use or transport mechanism.

Final answer: B