Answer :
Final answer:
The best candidate to donate blood is the 3) 20-year-old who weighs 47.7 kg (105lb), as they meet the minimum age and weight requirements for blood donation
Explanation:
The best candidate to donate blood among the listed patients is the 20-year old who weighs 47.7 kg (105lb). According to general blood donation criteria, the minimum age for blood donation is 16 years, which rules out the 15-year old candidate. There is no upper age limit as long as the individual is healthy, so age alone does not disqualify the 65- and 67-year-old candidates.
However, weight is also an important consideration. The minimum weight requirement for blood donation is usually set at 50 kg (110 lb) to ensure donor safety and an adequate quantity of blood for donation. Therefore, the 67-year old who weighs 44.4 kg does not meet the weight criteria. Considering both age and weight, the 20-year old weighing 47.7 kg is the only candidate who meets the necessary requirements for blood donation, assuming all other health factors are suitable.
