Under the 21st amendment to the 1973 Constitution, special courts had been established to deal with cases related to ___.

The 21st Amendment to the 1973 Constitution of Pakistan was passed in 2015, primarily in response to the horrific Peshawar school attack. This amendment established special military courts to deal specifically with cases related to terrorism. Its aim was to expedite trials and convictions of individuals involved in terrorist activities. Option B is the most precise answer. While militancy, extremism, and religious intolerance are related concepts, the amendment's focus for these special courts was explicitly on combating terrorism.