Advocates of a large-scale space-defense research project

We're asked for 4 answer choices that WEAKEN the conclusion. (Note: this does NOT mean to look for one answer that strengthens! It's often the case that we'll find 4 answers that weaken and one that's irrelevant.)

First, let's determine where the argument is flawed:

Premises: since government-sponsored research will have civilian applications, civilian businesses will reap the rewards of government-developed technology.

Conclusion: the space project will represent a net benefit to civilian business.

Logical flaws / missing information:
- just because there are civilian applications, does that mean businesses will reap rewards? What if there are patents that businesses can't use? What if it will be too expensive for businesses to utilize the technology?
- "net benefit to civilian business" means overall. But what if this technology benefits certain businesses while disadvantaging others?
- what about tradeoffs? If the government is diverting funds to this program that would otherwise have been spent helping businesses, then businesses in general could be worse off.

Let's evaluate the answer choices:

(A) The development of cost-efficient manufacturing techniques is of the highest priority for civilian business and would be neglected if resources go to military projects, which do not emphasis cost efficiency.
- This leads us to believe that civilian businesses will not be helped, since we're no longer prioritizing cutting costs.

(B) Scientific and engineering talent needed by civilian business will be absorbed by the large-scale project.
- If civilian businesses no longer have the best talent, they will be hurt by this project. This weakens.

(C) Many civilian businesses will receive subcontracts to provide materials and products needed by the research project.
- This would make businesses better off, so this strengthens the argument, not weakens.

(D) If government research money is devoted to the space project, it will not be available for specifically targeted needs of civilian business, where it could be more efficiently used.
- If money is diverted away from businesses to invest in the project, then this weakens the idea that the project will help businesses.

(E) The increase in taxes or government debt needed to finance the project will severely reduce the vitality of the civilian economy.
- If the economy is less vital overall, then civilian businesses will be hurt in the process, so this weakens the argument.

The only answer choice that does not weaken the argument is C.