Trapezoid A B C D has parallel sides \overline{A B} of length 33 and \overline{C D} of length 21 . The other two sides are of lengths 10 and 14 . The angles at A and B are acute. What is the length of the shorter diagonal of A B C D ?
Answer Choices
A. 10 \sqrt{6}
B. 25
C. 8 \sqrt{10}
D. 18 \sqrt{2}
E. 26