Ben Is Willing to Work for $4/hour and an Employer

Ben is willing to work for $4/hour and an employer is willing to hire Ben for $7/hour. Which of the following statements is TRUE?

A) A minimum wage of $7.50/hour would prevent this mutually beneficial exchange.
B) Minimum wages do not prevent mutually beneficial exchanges.
C) A minimum wage of $4.50/hour would prevent this mutually beneficial exchange.
D) A minimum wage of $3.50/hour would prevent this mutually beneficial exchange.