I chose C. The following is my reasoning. Hope to receive comments, if any, from you guys
If military aid to Latin American countries is to be stopped because it creates instability in the region, then all foreign aid must be stopped.
Structure: If a particular type of A gets B because that type makes something, then all types of A get B too.
(A) If a war in Central America is to be condemned because all killing is immoral, then all war must be condemned.=> Wrong. Reason cited must come from the particular war in CA only, while "all killing" refers to a feature of all.
(B) If charitable donations are obligatory for those who are rich, then it is certain that the poor will be provided for.=> Wrong. No reason is mentioned. Furthermore, the conclusion should be generalizing all types, rather than switching to a new type - "the poor".
(C) If the fascist government in Chile is to be overthrown because it violates the rights of the people, then all government must be overthrown.=> CORRECT! It closely follows the above structure
(D) If a proposed weapons system is to be rejected because there are insufficient funds to pay for it, then the system must be purchased when the funds are available.=> Wrong. This option mentions no generalization, instead, it focuses on "a proposed weapons system".
(E) If a sociological theory is widely accepted but later proven wrong by facts, then a new theory should be proposed that takes account of the additional data. => Wrong. No reason is cited.