Which substance can generally be applied to reduce irritation caused by an ant bite?

Correct answer: Mild baking soda solution

An ant bite commonly injects formic acid, which contributes to the burning or irritation. A mild baking soda solution is weakly basic and can help neutralise some of this acid at the skin surface, so option A is the suitable school-level answer. Vinegar, lemon juice, and another dilute acid are acidic and would not provide the intended neutralising effect. The solution should be mild and applied safely; severe reactions require medical attention.