Which of the following individuals is eligible to donate whole blood?

The correct choice hinges on the eligibility criteria for blood donation. In general, individuals must be in good health without any disqualifying health conditions.

A 17-year-old in excellent health is eligible to donate blood, as long as they meet the required age and health criteria set by blood donation organizations. A 19-year-old taking antibiotics for acne may be considered eligible depending on the type and dosage of the antibiotics, since certain antibiotics can temporarily disqualify someone from donating blood. However, many antibiotics do not prevent donation if the individual is feeling well overall.

A 25-year-old recovering from a cold could also be eligible, but the person must be completely symptom-free, meaning no lingering effects such as fever or cough should be present on the day of donation.

A 30-year-old on blood pressure medication can still donate blood, provided their blood pressure is stable and there are no other contraindications related to their health status or medication.

Thus, while the options include varying levels of eligibility based on health conditions, the most universally acceptable eligibility pertains to the individual who is in stable health without any medications or conditions that would pose a risk, which may apply to the individual in option B given proper context about their health condition.