Final answer:
NH2CH3 and CH4 are most likely to form a homogeneous solution.
Step-by-step explanation:
The pair of substances that are most likely to form a homogeneous solution are NH2CH3 and CH4.
Both NH2CH3 (methylamine) and CH4 (methane) are small organic molecules that are able to mix together uniformly in all proportions. This is because they are both nonpolar molecules, meaning they have similar intermolecular forces and can dissolve in each other easily.