I believe the answer is a because 2 times 12 is 24. Hope this helped
Answer: |x+2|=xF2+4
Explanation: not sure if this is right im just guessing
The first bond between two atoms is always a sigma bond and the other bonds are always pi bonds and a hybridized orbital cannot be involved in a pi bond. Thus we need to leave one electron (in case of Carbon double bond) to let the Carbon have the second bond as a pi bond.