A very wide rectangular channel carries a discharge (Q) of $70 \mathrm{~m}^3 / \mathrm{s}$ per meter width. Its bed slope changes from $0.0001$ to $0.0009$ at a point $\mathrm{P}$, as shown in the figure (not to scale). The Manning's roughness coefficient of the channel is $0.01.$ What water surface profile(s) exist(s) near the point $\mathrm{P}$?
- $\mathrm{M}_2$ and $\mathrm{S}_2$
- $\mathrm{M}_2$ only
- $\mathrm{S}_2$ only
- $\mathrm{S}_2$ and hydraulic jump