Concept:
Lithium can cause cutaneous and mucosal adverse effects, including oral lesions and lichenoid drug reactions. Such lesions can cause burning sensation, especially with spicy food.
Step 1: Identify the symptom pattern.
Oral lesions with burning on spicy food suggest an inflammatory mucosal lesion.
Step 2: Relate with drug-induced lesion.
Lithium is known to cause dermatological and mucosal adverse effects, including lichenoid eruptions.
Step 3: Select the responsible drug.
Among the options, the drug most likely responsible is:
\[
\text{Lithium}
\]
Therefore, the correct answer is Lithium.