Final answer:
The relation between IMF and melting point is a direct correlation, meaning that as the strength of the IMF increases, the melting point of a substance also increases.
Step-by-step explanation:
The relation between IMF (Intermolecular Forces) and melting point can be characterized as a direct correlation (Option A). This means that as the strength of the IMF increases, the melting point of a substance also increases. Conversely, as the strength of the IMF decreases, the melting point decreases as well. For example, substances with strong IMF, such as metals, have high melting points, while substances with weak IMF, such as gases, have low melting points.