Points A,B and C on a circle of radius r are situated so that AB=AC,AB>r, and the length of minor arc BC is r. If angles are measured in radians, then AB/BC=
[asy]
draw(Circle((0,0), 13));
draw((-13,0)--(12,5)--(12,-5)--cycle);
dot((-13,0));
dot((12,5));
dot((12,-5));
label("A", (-13,0), W);
label("B", (12,5), NE);
label("C", (12,-5), SE);
[/asy]
<spanclass=′latex−bold′>(A)</span>21csc41<spanclass=′latex−bold′>(B)</span>2cos21<spanclass=′latex−bold′>(C)</span>4sin21<spanclass=′latex−bold′>(D)</span>csc21<spanclass=′latex−bold′>(E)</span>2sec21