Step 1: Understanding the Concept.
This is a word-pair analogy question. We must first name the relationship shown by "exacerbate : mitigate" in words, then apply that same rule to pick the matching option.
Step 2: Key Rule or Approach.
Define both given words. "Exacerbate" means to make something worse or more severe. "Mitigate" means to make something less severe or easier to deal with. Since one word means "worsen" and the other means "lessen", the rule connecting them is: this is a pair of antonyms built around the idea of severity, one increasing it, the other reducing it. Any correct option must be a pair of words that are also antonyms carrying this same worsen-versus-lessen sense.
Step 3: Detailed Explanation.
Apply the rule to each option in turn.
"Aggravate" means to worsen, and "alleviate" means to lessen or ease. This pair fits the worsen-versus-lessen antonym rule exactly.
"Alleviate" (to ease) paired with "precipitate" (to trigger suddenly) fails, since "precipitate" is not about severity at all, so it cannot be an antonym of "alleviate" in this sense.
"Aggravate" (to worsen) paired with "precipitate" (to trigger suddenly) fails for the same reason: "precipitate" does not mean "to lessen".
"Emancipate" (to free from control) and "exonerate" (to clear of blame) are both about releasing a burden, so they are near-synonyms, not antonyms, and this pair fails the rule.
Only the pair "aggravate : alleviate" satisfies the antonym rule built on severity, exactly matching "exacerbate : mitigate".
Step 4: Final Answer.
The word pair that correctly completes the analogy is "Aggravate : Alleviate", option (A).