Theresa is comparing the length of four magazine articles. The first article begins on page 1 and ends on page 7. The second article begins on page 17 and ends on page 24. The third article begins on page 28 and ends on page 31, and the fourth article begins on page 52 and ends on page 56. What is the median number of pages in these articles?
(A)4 (B)5 (C)6 (D)7 (E)8
C