Which of the molecules below shows geometric isomerism? A) C5H10 B) C3H6 C) C4H6 D) C4H10O E) C4H10

Geometric isomerism, also known as cis-trans isomerism, occurs when there is restricted rotation in a molecule, which is usually due to the presence of a double bond or a ring structure. This leads to different spatial arrangements of the same atoms, hence the term 'geometric'.

Let's analyze each option:

A) C5H10: This molecule could be a straight chain alkene with a double bond (pent-2-ene) or a cycloalkane (cyclopentane). Both structures can show geometric isomerism.

B) C3H6: This molecule is propene, which has a double bond but not enough carbons to form geometric isomers.

C) C4H6: This molecule could be buta-1,3-diene or cyclobutene. Both structures can show geometric isomerism.

D) C4H10O: This molecule could be butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, or 2-methylpropan-2-ol. None of these structures can show geometric isomerism as they do not have a double bond or a ring structure.

E) C4H10: This molecule is butane, which is a straight chain alkane. It cannot show geometric isomerism as it does not have a double bond or a ring structure.

So, the molecules that show geometric isomerism are A) C5H10 and C) C4H6.