a tough sc

The local school board after extensive research discovered that because the current physics curriculum had little direct relevance to today's world, physics classes attracted few high school students.

(A) had little direct relevance to today's world, physics classes attracted
(B) has little direct relevance to today's world, physics classes have attracted
(C) has had little direct relevance to today's world, physics classes attracted
(D) has had little direct relevance to today's world, physics classes have attracted
(E) has little direct relevance to today's world, physics classes attracted

各位高手觉得 这道题陈述的客观事实 所以改用现在时。 还是与discovered 时态一致都用过去的时态？

是不是如果是第一种情况就选 b 第二种情况选 a???