Final answer:
The proliferative response of the soft tissue to an irritant is best exemplified by a pyogenic granuloma. This lesion is characterized by an overgrowth of tissue due to various stimuli, as opposed to an infection or ulcer.
Step-by-step explanation:
The proliferative response of the soft tissue to an irritant is characterized by an overgrowth of tissue as part of the healing process. Out of the options provided, pyogenic granuloma is a condition that represents a proliferative response. Pyogenic granulomas are vascular lesions that form as a response to various stimuli including chronic irritation, hormonal changes, or physical trauma. The name is somewhat of a misnomer because they are not infectious (pyogenic) by nature and do not contain granulomas histologically.
On the other hand, cellulitis represents a bacterial infection that manifests as a painful, red rash. An abscess is a pus-filled lesion often caused by infection, while an aphthous ulcer is a small, painful sore that may appear on the inside of the mouth and is not a proliferative response to an irritant in the context of overgrowth of tissue.