This problem is subtle; its challenges and rewards lie in tricky language details.
The stimulus opens with its conclusion_ in question form, no less! The conclusion reduces to:
The government, rather than businesses or universities, should fund a network of supercomputers.
Two premises support the conclusion:
1. No business or university can afford to purchase an entire network by itself.
2. No business or university wants to invest in a part of a network if no mechanism exists for coordinating a whole network.
We want to identify a weakness in the argument... hmmm... let’s go to the answer choices.
(E) seems like it could be eliminated by the second premise. No business or university wants to invest in a coordinated whole, right? How, then, could they cooperate to build that whole? But notice that the second premise comes in conditional form. It tells us that no business wants to invest in a part of a network IF no mechanism exists for coordinating establishment of the network as a whole. But perhaps this mechanism does indeed exist! The argument never eliminates this possibility. Businesses and universities might want to collaboratively invest in this case. (E) is correct.
(A) is out of scope. The argument concerns who should pay for the network, not how it will be established. Also, no "dilemma" is ever outlined.
(B) is wrong, although it is tricky. The argument never defines the supercomputer network as national, so it doesn’t need address whether or not an international network is possible.
This answer choice could be temptingly taken to identify a source of $$ beyond the government, industry, or universities. Why does the inability of universities and businesses to pay for a supercomputer network mean that government must fund the network? Don’t other sources of funding exist?
However, (B) articulates the possibility of an international supercomputer network, not an internationally funded supercomputer network. (B) fails to adequately address this weakness.
(C) is similar to (A). The argument revolves around funding the supercomputer network, not maintaining it.
(D) is way, way, way out of scope. There’s nothing about science or national preeminence in the argument.
Hope this helps!