Using the standard 26-letter alphabet, how many different groups of 4 letters are possible, if exactly two letters are chosen from a, e, i, o ,u and two letters are chosen from all the remaing letters except for y, and a letter can be used more than once? (A) 500 (B) 1900 (C) 2500 (D) 3150 (E) 6300 Recognize the GMAT Topic Being TestedThis is a combination, in which order doesn???t matter.