GATE2020-CE-1-1

Question

In the following partial differential equation, $\theta$ is a function of $t$ and $z$, and $D$ and $K$ are functions of $\theta$$$D(\theta)\frac{\partial^2\theta}{\partial z^2}+\frac{\partial K(\theta)}{\partial z}-\frac{\partial\theta}{\partial t}=0$$

The above equation is 

• A. a second order linear equation
• B. a second degree linear equation
• C. a second order non-linear equation
• D. a second degree non-linear equation