Solve the Problem $\left( { } ^ { \circ } \mathrm { C } \right)$

Multiple Choice

Solve the problem.
-The relationship between Celsius $\left( { } ^ { \circ } \mathrm { C } \right)$ and Fahrenheit $\left( { } ^ { \circ } \mathrm { F } \right)$ degrees of measuring temperature is linear. Find an equation relating ${ } ^ { \circ } \mathrm { C }$ and ${ } ^ { \circ } \mathrm { F }$ if $10 ^ { \circ } \mathrm { C }$ corresponds to $50 ^ { \circ } \mathrm { F }$ and $30 ^ { \circ } \mathrm { C }$ corresponds to $86 ^ { \circ } \mathrm { F }$ . Use the equation to find the Celsius measure of $31 ^ { \circ } \mathrm { F }$ .

A) $\mathrm { C } = \frac { 9 } { 5 } \mathrm {~F} - 80 ; - \frac { 121 } { 5 } \circ \mathrm { C }$
B) $\mathrm { C } = \frac { 5 } { 9 } \mathrm {~F} - \frac { 160 } { 9 } ; - \frac { 5 } { 9 } { } ^ { \circ } \mathrm { C }$
C) $C = \frac { 5 } { 9 } \mathrm {~F} - 10 ; \frac { 65 } { 9 } \circ \mathrm { C }$
D) $\mathrm { C } = \frac { 5 } { 9 } \mathrm {~F} + \frac { 160 } { 9 } ; 35 ^ { \circ } \mathrm { C }$