$\text { The resistance } R \text { of a certain type of resistor is } R = \sqrt { 0.009 T ^ { A } - 4 T + 100 } \text {, where } R \text { is }$

Multiple Choice

$\text { The resistance } R \text { of a certain type of resistor is } R = \sqrt { 0.009 T ^ { A } - 4 T + 100 } \text {, where } R \text { is }$ measured in ohms and the temperature T is measured in degrees Celsius. Use a computer algebra system to find the critical number of the function. Round numerical values in your answer to the Nearest whole number.

A) $T = 6 ^ { \circ }$
B) $T = 11 ^ { \circ }$
C) $T = 3 ^ { \circ }$
D) $T = 5 ^ { \circ }$
E) $T = 15 ^ { \circ }$