Which of the following statements is TRUE? A. T-cells pass both tests by responding to the cells they come into contact with. B. T-cells pass the first test by responding and the second test by not responding to the cells they come into contact with. C. T-cells pass the first test by not responding and the second test by responding to the cells they come into contact with. D. T-cells pass both tests by not responding to the cells they come into contact with.