Final answer:
Option (3), The presence of slurred speech and stasis of food in the mouth suggests a need to investigate possible dysphagia. Drooling would be the additional assessment to cluster with these signs, as it may indicate a dysfunction in swallowing, possibly related to neurological impairments involving cranial nerves.
Step-by-step explanation:
If a patient presents with slurred speech and stasis of food in the mouth, additional assessments should consider neurological functions and the potential for dysphagia (difficulty in swallowing). Since stasis of food may indicate a problem with swallowing, known as deglutition, it would be appropriate to look for other symptoms that can be associated with disorders affecting the oral cavity and pharynx.
Based on the information provided, the additional assessment that should be clustered with slurred speech and stasis of food in the mouth would be drooling. This is because drooling can be a sign of impaired swallowing mechanisms or issues with muscle control in and around the oral cavity, both of which may relate to the current symptoms. It is also influenced by neurological functions, particularly those involving the cranial nerves, which can be assessed through a neurological exam.
Plaque and halitosis could be relevant to oral hygiene but are less directly connected with the neuromuscular control required for deglutition. Dyspepsia is related to indigestion and would not be the most immediately relevant to the issue of stasis of food and slurred speech.