Final answer:
1,3-dichloropropane contains at least one stereogenic center, while the other compounds do not. The correct option is (a).
Step-by-step explanation:
The compound 1,3-dichloropropane contains at least one stereogenic center. A stereogenic center, also known as a chiral center, is a carbon atom that is bonded to four different groups. In 1,3-dichloropropane, the central carbon atom is bonded to two chlorine atoms, a hydrogen atom, and a methyl group. Since these four groups are different, the compound has one stereogenic center.
The other compounds listed do not contain any stereogenic centers. 1,3-dimethylcyclobutane has two methyl groups attached to the same carbon atom, making it achiral. 2,2-dichloropropane and 3-methylpentane do not have any carbon atoms bonded to four different groups, so they do not have stereogenic centers.