Correct option is C
The correct option to fill in the blank is (c) Efficiently.
Explanation: "Efficiently" fits the context as it means working in a well-organized and productive manner, which aligns with being decisive and accurate.
Meanings of other options:
· Anxiously: With worry or nervousness, inappropriate here.
· Elaborately: In a detailed and complicated manner, which doesn't suit the sentence.
· Precisely: Exactly or accurately, but not as appropriate as efficiently for describing work style.