41. Suppose you are labeling a population of cells growing asynchronously with [H]thymidine. G₁ is 6 hour, S is 6 hours, G2 is 5 hours, and M is 1 hour. What percentage of the cells would have labeled mitotic chromosomes if you chased the cells for 18 hours? (A) One-third of the cells (B) None of the cells (C) Two-third of the cells