GRE Reading Comprehension: Manhatton-GRE阅读Manhatton - Z554GY8S07K1V52GA$

The phrase "seemingly haphazard" is meant to indicate that: A. the process of programmed genetic mutation deserves further study. B. the production by T-cells of "unproductive cells" is wasteful. C. genetic recombination may appear random, but is not. D. T-cells are essential to proper immune system functioning. E. programmed genetic mutation can be dangerous to an organism.