It is a multiple choice question:
Which compound does not show stereoisomerism?
I can eliminate A and C as they show geometrical isomerism as there is a double bond with different priority groups on either side so these can form E and Z isomers.
Leaving B and D and by the nature being an alkane means that they cannot have geometrical isomerism as they have no double bond. Leaving us to identify which one, therefore, has optical isomerism. Which occurs from my understanding from a chiral center where a carbon is bonded to four different groups. But I cant apply this knowledge to understand why it is D as carbons in B and D are bonded to four atoms so surely they both show optical isomerism which is incorrect given the answer.