The partial differential equation $\frac{\partial u}{\partial t}+u \frac{\partial u}{\partial x}=\frac{\partial^{2} u}{\partial x^{2}}$ is a
(A) linear equation of order 2
(B) non-linear equation of order 1
(C) linear equation of order 1
(D) non-linear equation of order 2
The partial differential equation $\frac{\partial u}{\partial t}+u \frac{\partial u}{\partial x}=\frac{\partial^{2} u}{\partial x^{2}}$ is a
(A) linear equation of order 2
(B) non-linear equation of order 1
(C) linear equation of order 1
(D) non-linear equation of order 2