Which nerve provides sensory innervation to the soft palate?

The lesser palatine nerve is the correct choice because it is specifically responsible for providing sensory innervation to the soft palate. This nerve branches off from the maxillary division of the trigeminal nerve (V2) and innervates the mucosa of the soft palate and the tonsillar region, which are essential areas for sensory functions such as taste and sensation.

Other nerves mentioned have different roles. For instance, the greater palatine nerve primarily supplies the hard palate, while the nasopalatine nerve innervates the anterior hard palate and the incisive papilla area. The posterior superior alveolar nerve mainly provides sensory innervation to the upper molars and adjacent buccal tissues, but not to the palate itself. Thus, the lesser palatine nerve is uniquely suited for sensory innervation of the soft palate, distinguishing it from the functions of the other nerves listed.