Final answer:
Money market instruments are short-term debt securities that are highly liquid and low risk. The characteristic that is not true for a money market instrument is low marketability.
Step-by-step explanation:
Money market instruments are short-term debt securities that are highly liquid and low risk. They are typically characterized by a maturity of less than 1 year, high liquidity, and low marketability.
However, the correct answer to the question is D. Low Marketability because money market instruments are known for their high marketability, meaning they can be easily bought or sold in the market.