Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Shreyasi majumdar 1
I think the ques is about c=c bond length since they have used longest. In that case, higher the no. of alpha H higher will be c=c length. so option d is correct as there are 6 alpha H