What is the order and degree of the differential equation $(\frac{d^2s}{dt^2})^2+\frac{d^2s}{dt^2}+t\frac{ds}{dt}=0$?

order 2 degree 1 order 1 degree 2 order 1 degree 1 order 2 degree 2

order 2 degree 2

Highest order derivative is $\frac{d^2s}{dt^2}$. So order 2. The power of $\frac{d^2s}{dt^2}$ is 2 so degree 2.