The coordinates of △ABC are A(5,7), B(11,7), C(3,y), with y>7. The area of △ABC is 12. What is the value of y?[asy]
size(10cm);
draw((5,7)--(11,7)--(3,11)--cycle);
label("A(5,7)", (5,7),S);
label("B(11,7)", (11,7),S);
label("C(3,y)", (3,11),W);
[/asy]<spanclass=′latex−bold′>(A)</span>8<spanclass=′latex−bold′>(B)</span>9<spanclass=′latex−bold′>(C)</span>10<spanclass=′latex−bold′>(D)</span>11<spanclass=′latex−bold′>(E)</span>12