Explain why the cis and trans isomers of the given alkene show no coupling between the a and c, as well as between the b and c protons.

• A. There is no coupling between a and c and between b and c protons because they are both too near to each other.
• B. There is no coupling between a and c and between b and c protons because they are 6 and 4 pi bonds away from each other, respectively.
• C. There is no coupling between a and c and between b and c protons because they are 4 and 6 sigma bonds away from each other, respectively.
• D. There is no coupling between a and c and between b and c protons because they are 4 and 6 pi bonds away from each other, respectively.

Answer: (C)