Final answer:
Option (A), Caius Ligarius's statement is an allusion to the conspiracy to assassinate Caesar, implying that harm must be done to the current state to bring change.
Step-by-step explanation:
When Caius Ligarius says, "But are not some whole that we must make sick?" (line 328), he is referring to the necessity of causing harm to something that is currently whole or unbroken for a perceived greater good. Specifically, in the context of Shakespeare's Julius Caesar, Ligarius is alluding to the conspiracy to assassinate Caesar.
The 'whole' refers to the current state of affairs or the body politic under Caesar's rule, which the conspirators believe must be 'made sick,' or disrupted, by their actions to bring about change. Thus, the correct answer to the given question is A) Assassinate another conspirator.