Final answer:
In the context of theater attendance policies, the correct option to complete the sentence is c. 'arriving,' indicating that anyone who is in the process of arriving after a play has started will have to wait until the interval to enter.
Step-by-step explanation:
When attending a theater production, it is important to consider the rules regarding latecomers. Many theaters have specific policies stating that anyone who arrives after the play has started may not be allowed to enter until the intermission. This rule ensures that the performance is not disrupted for the actors and the audience already seated and engaged in the show.
In the context of the given sentence, the correct grammatical form should indicate an action that happens after the start of the play and before the person tries to enter the theater. Therefore, the right option to complete the sentence 'Anyone........ after the start of the play is not allowed in until the interval.' would be 'arriving', highlighting the continuous action of arriving at the theater.
Considering grammar use and the context provided, the sentence would correctly read as: 'Anyone arriving after the start of the play is not allowed in until the interval.'