If Tepid: Hot then ________

The relationship between "Tepid" and "Hot" is one of degree: "Tepid" means lukewarm or mildly warm, while "Hot" represents a more intense level of warmth. Similarly, "Joy" is a feeling of happiness or pleasure, while "Ecstasy" is a heightened, more intense state of joy. This mirrors the escalation in intensity seen in the original pair. The other options—a) Jealousy : Envy, b) Hatred : Antipathy, and c) Unity : Harmony—do not consistently reflect the same clear increase in degree. Therefore, the best answer is d) Joy : Ecstasy.