Final answer:
Athletes should acclimatize for 2-3 weeks before a major competition to allow their bodies to make necessary physiological adjustments for optimal performance.
Step-by-step explanation:
For optimal performance, athletes should ideally acclimatize to a new environment for 2-3 weeks before a major competition. Acclimatization allows the body to adjust to different conditions such as altitude, temperature, humidity, and time zone changes. The adaptive changes that occur include physiological adjustments like the efficiency in blood oxygen delivery and temperature regulation to support the athlete’s performance levels. While a period of 1-2 months might be too lengthy and impractical for many competitive schedules, 1-2 days is usually insufficient for the body to fully adjust. Therefore, the correct answer here is (a) 2-3 weeks, which is a feasible timeframe for an athlete in good condition to attain acclimatization and perform at their best.