no humidity in order to give the same heat effect. One such index is given by the function below, where Tis the air temperature, in degrees Fahrenheit, and His the relative humidity, expressed as a decimal.Th=1.93T-1.09(1-H)(T-64)-56.7delThdelH=-1.09(T-64)Choose the correct answer below.A. The partial derivative shows that where T<64,Th will increase by a factor of1.09 units. Where T>64,Th will decrease by a factor of1.09 units.B. The partial derivative shows that where T<64,Th will increase by a factor of1.09 units. Where T64,Th will decrease by a factor of1.09 units.C. The partial derivative shows that where T64,Th will decrease by a factor of1.09 units. Where T<64,Th will increase by a factor of1.09 units.D. The partial derivative shows that where T>64,Th will increase by a factor of1.09 units. Where T<64,Th will decrease by a factor of1.09 units.