The answer is: A It increased both her intensity and her workout time.
Intensity refers to how hard you exercise and workout time refers to how long your exercise your body. By adding another mile she would most likely increase the time needed to complete her workout and it would also become harder for her to complete it since her cardiovascular system would have to face more workload.
By adding another mile, she is both increasing the intensity (because she is running an extra mile), while also increasing her workout time (considering the fact that adding distance also adds time).
