Final answer:
The eligible blood donor is the 25-year-old who received a flu shot last week, as flu shots do not disqualify individuals from donating blood.
Step-by-step explanation:
The phlebotomy technician should identify that the 25-year-old who received a flu shot last week is able to donate blood. There are common misconceptions about who can and cannot donate blood.
Notably, having high cholesterol, being on blood pressure medication, or having a recent flu shot does not disqualify someone from donating blood. In this scenario, the 17-year-old with a recent piercing may need to wait, depending on the timing and state regulations concerning infectious risk. The 30-year-old with a history of heart disease may be disqualified based on the specifics of their condition.
The 40-year-old on medication for hypertension can donate as long as their blood pressure is below 180/100 at the time of donation. However, the 25-year-old is eligible because receiving a flu shot has no effect on one's ability to donate blood, and they can even donate on the same day they receive the shot.