Evaluate the spontaneity of a reaction in a biological system if ΔG° = 20 kJ/mol under standard conditions and ΔG = -5 kJ/mol under physiological conditions.

• A. The reaction is non-spontaneous under standard conditions but spontaneous under physiological conditions.
• B. The reaction is spontaneous under both standard and physiological conditions.
• C. The reaction is spontaneous under standard conditions but non-spontaneous under physiological conditions.
• D. The reaction is non-spontaneous under both standard and physiological conditions.

Answer: (A)