Answer: Yes, the employment contract has been breached, but the non-competition agreement has not been breached.
Step-by-step explanation:
The options are:
a. Yes, the employment contract has been breached, but the non-competition agreement has not been breached.
b. No, the employment contract has not been breached, but the non-competition agreement has been breached.
c. Yes, both contracts have been breached.
Based on the information given in the question, we can state that the employment contract has been breached. This is because Xuechen signed an employment contract to work as a chef for one of Chicago's best restaurants for a period of three years but she left shortly to work as a manager at another Chicago restaurant. On the other hand, the non-competition agreement has not been breached.