Final answer:
The expression that could be used to determine when the play has reached capacity is option A) 350 + 23h.
Step-by-step explanation:
The expression that could be used to determine when the play has reached capacity is option A) 350 + 23h. This is because the capacity of the theater is 350 seats, and the play is expected to sell 23 tickets per hour once they go on sale. So, if we multiply 23 by the number of hours the tickets have been on sale (represented by h) and add it to the initial capacity of 350, we will get the total number of tickets sold. When this number equals the capacity of 350, it means the play has reached capacity.