Explanation
Mitigation is a risk response that seeks to lower the risk's probability and/or impact. It is not one of the three categories of risk tolerance.

Explanation
Of all the choices, the belief about the project team members is the best example of an assumption. An assumption is something that is believed to be true, but it has not been proven to be true.
Answer B is incorrect. This is an example of a constraint. Answer D is incorrect. This is an example of a requirement.
Answer C is incorrect. This is an enterprise environmental factor, which could also be seen as a requirement.

Explanation
An onion diagram shows the relative influence, impact, and relation of stakeholders by plotting them closer to or farther away from the solution. It is called an onion diagram because plotting of the stakeholders is done in ovals which, when completed, looks like an onion sliced in half.
Answer D is incorrect. A tornado diagram is often used to show opposing forces for a solution or issue.
Answer A is incorrect. The RACI matrix explains the roles of the people involved in business analysis
activities. It depicts stakeholders as having one or more of the following responsibilities for a given task or deliverable:
[R]. Responsible does the work
[A]. Accountable is the decision maker (only one)
[C]. Consulted must be consulted prior to the work and gives input.
[I]. Informed means that they must be notified of the outcome
Answer C is incorrect. A control chart is a quality control tool that shows the results of measurements over time.

Quantitative performance measure is being practiced by the software development company that evaluates solutions against the number of defects reported in the testing phase. Quantitative performance measures are those that use numerical values or statistics to assess the performance of a solution or an organization. They can help to measure aspects such as quality, efficiency, productivity, profitability, customer satisfaction, etc.
The number of defects is a quantitative measure of quality that indicates how well a solution meets its specifications and expectations. References: : Quantitative Performance Measures