Final answer:
The stability of stereoisomers is primarily determined by energy minimization; the more stable isomer has the lower potential energy and less steric strain, as seen in conformations of butane and monosubstituted cyclohexanes. Hence, the correct option for which is the more stable stereoisomer is B) Energy minimization.
Step-by-step explanation:
In considering the stability of stereoisomers, several factors can play a role, but the most common one is the energy minimization principle. For most stereoisomers, the conformation with the lowest potential energy will be the most stable. For example, in conformational isomers of butane, the anti-conformation is more stable than the gauche-conformation because it has less steric strain and, thus, a lower energy state. Similarly, conformations of monosubstituted cyclohexanes demonstrate stability dependence on energy minimization; the chair conformation with a substituent in the equatorial position is more stable due to reduced 1,3-diaxial interactions compared to the axial position.
Optical activity and the presence of a chiral center are properties of certain stereoisomers and influence their ability to rotate plane-polarized light, but they do not inherently determine the stability of the molecule. The proper descriptor for justifying the stability of a stereoisomer is energy minimization.
Therefore, the correct answer to the question regarding which factor determines the more stable stereoisomer in a pair is B) Energy minimization.