Select the two statements that answer why it is important for Katharine Johnson to understand the causes of a variance before she evaluates performance.

Johnson should understand efficiency variances may arise for only one reason and she needs to know that reason before evaluating performance.

It is important for Johnson to understand that not all favorable material price variances are$$ "good news", because of the negative effects that can arise in the production process from the purchase of inferior inputs.

Johnson should understand efficiency variances may arise for many different reasons and she needs to know these reasons before evaluating performance.

It is important for Johnson to understand that all favorable material price variances are$$ "good news", because they are increasing profits.