Physiology General 0d71d19c Lifespan of fetal RBC is ? A Same as adult RBC B 1/4 of adult RBC C 1/2 of adult RBC D 2/3 of adult RBC High-Yield Explanation Ans. is 'd' i.e., 2/3 of adult RBC"Life span of fetal RBC is about 2/3' of the adult RBC, i.e. about 80 days."