Concept:The simple past tense refers to an action that ended at a specific time in the past.
Explanation:The sentence uses "took off", which is the simple past form of "take off".
A simple past action is completed at a definite past moment.
"Five minutes ago" gives that definite past moment correctly.
"Since five minutes" is incorrect because "since" needs a point of time, not a duration, and it is used with the present perfect.
"In the past five minutes" is used with the present perfect, not the simple past.
"By five minutes" does not show when the action happened.
Thus, the best completion is "five minutes ago".
Answer:B. five minutes ago.