Answer:The correct answer is D. both (a,c).
The sentence should read: "We're going to produce our project outline by Friday, the ninth."
The preposition "by" indicates a deadline or a timeframe for completing an action, and it is commonly used in this context.
So, the correct options are:
- By (indicating a deadline)
- On (indicating a specific date)
Therefore, the answer is D. both (a,c) - "on" and "by".
Explanation:
