Many people feel queasy while travelling on a bus on hilly roads.

Answer: Option A

Uneasy : causing or feeling anxiety; troubled or uncomfortable.
Mobile : able to move or be moved freely or easily.
Drowsy : sleepy and lethargic; half asleep.
Dynamic : (of a process or system) characterized by constant change, activity, or progress.
Queasy : slightly nervous or worried about something.

Synonym of Queasy is Uneasy