Answer:
Arousing
Step-by-step explanation:
Arousal is the state in which a person gets alert and conscious and awake. Arousal is stated that is control by our brain. There is a specific area that works in regulating arousal that is the reticulated activating system. The arousal will affect many states of mind such as emotions, motivation, consciousness, attention, etc.
Thus according to Zajonc, the mere presence of a roommate will arouse the attention, concentration, motivation, and emotions of the roommate while she was typing an email. Her reticulated activation system starts to work in that situation.