请大家帮助讨论一下，
我觉得答案是E，可是GIGI给出的答案是C？？？
Q13:
Is the measure of one of the interior angles of quadrilateral A-B-C-D equal to 60 degrees?
(1) Two of the interior angles of A-B-C-D are right angles.
(2) The degree measure of angle ABC is twice the degree measure of angle B-C-D.
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient. | 
