The consulting company you are working for is negotiating a contract with a large hospital to conduct a security assessment of its wireless network to confirm that it complies with federal privacy regulations and, if it doesn't, to aid in fixing any issues. The customer is proposing a fixed-price contract, but due to the potential complexity and unknown issues that may materialize, your consulting company would like to propose a solution that would limit their risk. What type or types of contracts would you suggest that your consulting company use and why?