Is there a way to have only one exit?

You could do with one exit if the building is less than or equal to 2 storeys, and the occupant load is less than 60, and floor area/travel distance is as perscribed within Table 3.4.2.1.A (e.g., Group D: 200 m² / 25 m). By the way sprinklered buildings get larger allowances per Table 3.4.2.1.B. Also Group A Div.1 never qualifies. per OBC: 3.4.2.1.(2), Tables 3.4.2.1.A & B.