Final answer:
Avoidant and schizoid personality disorders pertain to Cluster C personality disorders; the former involves a desire for intimacy but a fear of social interactions, while the latter indicates a preference for solitude. The correct option is C.
Step-by-step explanation:
Individuals with avoidant personality disorder desire intimacy but have a significant fear of it, which leads to avoidance of social interaction, whereas those with schizoid personality disorder generally prefer solitude and tend to avoid close relationships altogether.
These descriptions align with Cluster C personality disorders, as defined by the American Psychological Association in the Diagnostic and Statistical Manual of Mental Disorders (DSM). The desire for intimacy paired with a fear of it is especially characteristic of avoidant personality disorder while the preference for being alone is indicative of schizoid personality disorder.