Hi, bli2016.
Good question! Let's set aside the (A) for a moment and discuss our analysis and prephrase. The argument proceeds as follows:
- P1: The telescope under construction is way over budget.
- P2: If we cancel the telescope now, all the money already spent (more than the remaining cost) will have been wasted.
- Conclusion: We should not cancel the telescope.
The task is to frame a principle that strengthens this reasoning. To make a good prephrase, we should be clear on the connection we wish to establish. Notice that the conclusion above involves an implicit conditional connection between P2 and the statement in the conclusion. Let's clarify the sufficient and necessary conditions.
- Sufficient condition: Wasting money spent on telescope when less than half the total cost remains
- Necessary condition: Don't cancel the telescope
Now let's describe these conditions in more general language:
- Sufficient condition: Halt an expensive project when less than half the cost remains
- Necessary condition: Do not halt this project
Put this together to form a good prephrase:
- It is unwise to halt a project when less than half the cost remains.
Compare this prephrase to (A). Note that as you mentioned, the idea of the "agency's budget" is outside the scope of this question. However, furthermore, we could notice the conditional reasoning in this answer choice: "If it's advisable for a government agency to cancel a project, then the amount of money spent on the project must be small compared to the agency's overall budget"
Framed in contrapositive form: "If the amount of money spent on a project is large compared to the agency's budget, then the agency should not cancel the project."
Note that the necessary conditions here do sync up pretty well. We have as necessary conditions the idea that the agency shouldn't cancel. However, let's take a closer look at the sufficient conditions.
Even if we were to consider the counterfactual you propose—"amount spent large relative to overall budget for the project"—we'd still be missing the mark compared to (B). The issue here does not have to do with the
budget for the project but rather the total projected cost. We need to make a comparison between the amount spent versus the total projected cost and not between the amount spent and the initial budget.
With (B), we have a good match for our prephrase.
Good question and good reasoning. I hope this helps!