Answer:
The correct answer for this situation is:
Efficacy.
Explanation:
Proficiency means the best level of knowledge and performance about a certain task or competence, in an hour case, it is very easy to identify it was efficacy because it is a general concept that allows determining relativity between high performance, proficiency, and a task. Therefore we can deduct that efficiency or less cost and effort at performing a task is the concept o the matter.
