Answer: In the sentence provided, the meaning of the word "extempore" is (D) spur of the moment.
Explanation: The word "extempore" is an adjective used to describe something as done without previous preparation. In that way, the option that defines the meaning of "extempore" is D) spur of the moment. "Spur of the moment" is an expression used to refer to something that happens suddenly and without planning it, that is to say without premeditation.