Final answer:
The shelf life of whole collected blood at 4° C is about 42 days, with 35 days being the closest provided answer. This is different from the 120-day lifespan of individual red blood cells after they mature from reticulocytes.
Step-by-step explanation:
The shelf life of whole collected blood at 4° C is about 42 days. This is distinct from the lifespan of individual erythrocytes, or red blood cells, which circulate in the bloodstream for an average of 120 days after maturation from reticulocytes. When blood is donated and stored in a blood bank, it is usually kept at refrigerated temperatures to extend its shelf life while maintaining its quality and viability for transfusion. The correct answer to the question, based on the options provided, is 4) 35 days, since it is the closest to the actual shelf life of stored blood.