Negative symptoms manifest as:

Negative symptoms in the context of behavioral health, particularly in mental health disorders like schizophrenia, refer to a reduction or absence of normal emotional and behavioral functions. This can manifest as a lack of motivation, reduced emotional expression, and social withdrawal. Individuals may appear flat or unresponsive to emotional stimuli, showing diminished emotional reactions in situations where one would typically expect a response.

The presence of clear and expressive emotional displays and excessive communication and social engagement are characteristics of positive symptoms, which represent the addition of behaviors that are not typically present. Overactivity and emotional instability also align more with positive symptoms or other behavioral disorders, rather than the absence of behaviors seen in negative symptoms. Therefore, option A accurately describes the essence of negative symptoms by highlighting the absence or decrease in emotional and behavioral responses.