Which of the Following Are Linear Equations in Two Variables $y = x$

Multiple Choice

Which of the following are linear equations in two variables?

A) $y = x$
B) $\frac { 4 } { x } - \frac { 3 } { y } = - 1$
C) $2 w + 8 z = - 4 w + 3$
D) $y = x ^ { 2 }$
E) $2 x - x = 4$