Solve the Problem $C = \frac { 9 } { 5 } F - 80 ; - \frac { 121 } { 5 } { } ^ { \circ } \mathrm { C }$

Multiple Choice

Solve the problem.
-The relationship between Celsius (°C) and Fahrenheit (°F) degrees of measuring temperature is linear. Find an equation relating °C and °F if 10°C corresponds to 50°F and 30°C corresponds to 86°F. Use the equation to find
The Celsius measure of 31° F. A) $C = \frac { 9 } { 5 } F - 80 ; - \frac { 121 } { 5 } { } ^ { \circ } \mathrm { C }$
B) $\mathrm { C } = \frac { 5 } { 9 } \mathrm {~F} - \frac { 160 } { 9 } ; - \frac { 5 } { 9 } { } ^ { \circ } \mathrm { C }$
C) $C = \frac { 5 } { 9 } F - 10 ; \frac { 65 } { 9 } { } ^ { \circ } \mathrm { C }$
D) $C = \frac { 5 } { 9 } \mathrm {~F} + \frac { 160 } { 9 } ; 35 ^ { \circ } \mathrm { C }$