A:What's the plan while the boss is away? B:What I heard was that Maria __ the office. A: But has she ever done that before? is going to be running would be about to run is used to running would have run

The question is a fill-in-the-blank type of question in English language and literature. The correct answer is "is going to be running". This is because the context of the conversation is about a future event (the boss's absence), and the speaker is predicting what Maria is going to do in that future event. The phrase "is going to be running" is used to express a future plan or intention. The other options do not fit the context. "Would be about to run" is used to talk about a future event that is unlikely to happen. "Is used to running" is used to talk about a habit or something that someone does regularly. "Mould have run" is not grammatically correct.