Correct option is C
Weapons of mass destruction indeed include nuclear explosive weapons among others, and chemical weapons have been outlawed as weapons of mass destruction in the Chemical Weapons Convention. The statement that biological weapons are not included in the category of weapons of mass destruction is incorrect; biological weapons are considered weapons of mass destruction. The Chemical Weapons Convention indeed came into effect, but the correct statements related to the question are A and C, making the combination of these two the correct answer.