In Fred Griffith's experiments, harmless R strain pneumococcus became lethal S strain pneumococcus as the result of which of the following? 1)horizontal gene transfer 2)transduction 3)conjugation 4)transformation 5)genetic recombination
A) 2 only B) 4 only C) 2 and 5 D) 1, 3, and 5 E) 1, 4, and 5