Final answer:
The most liquid option among the given choices is a dollar bill, as it can be easily exchanged for goods or services.
Step-by-step explanation:
Liquidity refers to how easily one can exchange money or financial assets for a good or service. Among the options given, the most liquid is a dollar bill. Dollar bills are widely accepted as a medium of exchange and can be easily used for transactions. On the other hand, government bonds, corporate bonds, and mutual fund shares require a more complex process to convert them into cash.