Step 1: Understanding the idiom.
"Will not hold water" is an idiom meaning that something is not valid or convincing, which fits the context of the argument being weak or unconvincing.
Step 2: Analyzing the options.
- (A) will not hold water: This is the correct idiom, meaning the argument is not convincing or logical.
- (B) will not hold oil: This is not a correct idiomatic expression.
- (C) will not hold anything: This is not a common idiom and does not fit the context.
- (D) will drop everything: This is unrelated and does not apply to the meaning of an argument being weak.
Step 3: Conclusion.
The correct answer is (A) will not hold water, as it best conveys the meaning of an unconvincing argument.