Final answer:
H2Se is the molecule from the list given that exhibits only London dispersion forces because it is a nonpolar molecule with selenium and hydrogen.
Step-by-step explanation:
The question is related to intermolecular forces, specifically London dispersion forces (also known as London forces). Among the listed molecules - NF₃, K₂SO₄, H₂Se, OF₂, BeCl₂, CH₃OH - the one that exclusively exhibits London forces is H₂Se, a nonpolar molecule formed by selenium and hydrogen. While all molecules experience London forces to some extent, H₂Se does not have significant dipole-dipole interactions or hydrogen bonding like some of the others mentioned. Therefore, H₂Se is the correct answer.