Which of the following is an example of mitigation of damages? O Roger, who contracted with Bill to.

Which of the following is an example of mitigation of damages?
O Roger, who contracted with Bill to mow Roger's lawn, is awarded $100,000 after Bill breaches the lawn mowing agreement because Bill has entered into several lawn mowing agreements, but always fails to mow the lawns of his customers.
O Roger, who contracted with Bill to mow Roger's lawn, threatens Bill with a gun when he says he won't mow Roger's lawn.
O Roger, who contracted with Bill to mow Roger's lawn, hires Fred to mow the lawn after Bill breaches and then Roger sues Bill for the difference in cost between Fred&Bill's rates
O Roger, who contracted with Bill to mow Roger's lawn, is permitted to void the agreement with Bill after learning Bill never owned a lawn mower when he agreed with Roger to mow Roger's lawn