From the words lettered A to D, choose the word that best completes each of the following sentences.
This is an improvement...........your last report
Answer Details
The correct answer is "on".
Explanation: "Improvement on" means that the current report is better than the previous one, which is the intended meaning of the sentence. "Improvement of" implies that the report itself has been improved, while "Improvement over" is used when something has surpassed or exceeded another thing. "Improvement against" doesn't make sense in this context.