Answer: A) If she were impatient, she would not be suited for this work.
Explanation: The subjunctive mood is the verb form used to express a wish, a suggestion, a command, or a condition that is contrary to fact. From the given options, the sentence in which the subjunctive mood is correctly used, is the corresponding to option A: If she were impatient, she would not be suited for this work, notice that the subjunctive form of the verb "to be" is "were," the other sentence are all in the indicative mood.