A centigrade and Fahrenheit thermometer are dipped in boiling water. The water temperature is lowered until the Fahrenheit temperature observed is 140^ F . At that time the temperature registered by the centigrade thermometer is

Step-by-step solution

Temperature conversion from Fahrenheit to Celsius uses the formula: T_C = 5 9 (T_F - 32) . For T_F = 140^ F , substitute into the formula: T_C = 5 9 (140 - 32) = 5 9 108 = 5 12 = 60^ C . The result corresponds to option B .