Five students Adele, Betty,Carol, Doris, and Ellen- answered five questions on an exam consisting of two multiple-choice (a,b,c) questions and three true-or-false questions.

(1) They answered the questions as follows:

       I     II.    III.    IV.     V
Adele. a      a      t       t      t
Betty. b      b      t       f      t
Carol. a      b      t       t      f
Doris. b      c      t       t      f
Ellen. c      a      f       t      t

(2) No two students got the same number of correct answers.
Who got the most correct answers?