The correct answer is: C. has been flying
The sentence is in the present perfect continuous tense, which is used to talk about an action that started in the past and is still happening now. In this case, the action is “flying an airplane”. The speaker is saying that the person has been flying an airplane for 10 hours, and is still flying.
The other options are incorrect because they do not express the same meaning. Option A, “has flown”, is in the simple past tense, which is used to talk about an action that happened at a specific time in the past. Option B, “is flying”, is in the simple present tense, which is used to talk about an action that is happening now. Option D, “will fly”, is in the future tense, which is used to talk about an action that will happen in the future.
Here are some examples of how the present perfect continuous tense can be used:
- I have been working on this project for 2 hours.
- She has been waiting for you for 10 minutes.
- We have been playing soccer for 3 hours.
- They have been studying for the test for 2 days.