Hi Michaelangilo!
This stimulus contains conditional reasoning so we can diagram it:
Premise #1: Govt increases funding for civilian research
private patrons and industries believe civilian research is primarily govt responsibility
Premise #2: Private patrons and industries believe civilian research is primarily govt responsibility
private patrons and industries decrease contributions toward research
Conclusion:
Depress overall level of funding for civilian scientific research Govt increases funding for civilian research
With Assumption questions involving conditional reasoning, we are often looking for a gap in the conditional logic between the premises and the conclusion. Here, the author jumps from "private patrons and industries decrease contributions toward research" to "depress overall level of funding for civilian scientific research." So the author is assuming that the decrease in private funding that would happen after an increase in government funding would result in an overall decrease in funding. That's what answer choice (B) addresses: "Any increase in government funding would displace more private funding for civilian scientific research than it would provide." This answer choice tells us that the decrease in funding from private sources would be greater than the increase in funding from government sources, resulting in an overall decrease in funding.
Answer choice (D), on the other hand, states "Civilian scientific research cannot be conducted efficiently with more than one source of funding." This answer choice refers to efficiency of the research. But this is irrelevant to the argument. Nothing in the argument addresses the efficiency of the research. The argument is solely about funding amounts from different sources, not how efficiently the research can be conducted.
Hope this helps!
Best,
Kelsey