Which one of the following differential equations represents the family of straight lines, which are at unit distance from the origin ?

What is the order and degree, respectively of the differential equation whose solution is $$y = cx + {c^2} - 3{c^{3/2}} + 2$$, where c is a parameter?

The general solution of $${{dy} \over {dx}} = {{ax + h} \over {by + k}}$$ represents a circle only when

The order and degree of the differential equation $${\left( {1 + {{\left( {{{dy} \over {dx}}} \right)}^2}} \right)^3} = \rho {\left[ {{{{d^2}y} \over {d{x^2}}}} \right]^2}$$ are respectively