Final answer:
The tradeoff that agents make when deciding to save or invest is liquidity vs. potential returns.
Step-by-step explanation:
The tradeoff that agents make when they decide to save or invest is A. Liquidity vs. Potential Returns. When choosing to save, individuals prioritize immediate access to their money, which provides liquidity.
On the other hand, investing involves putting money into assets or ventures with the potential for higher returns but less immediate access to the funds.