If $W_1$, $W_2$ and $W_3$ represent the work done in moving a particle from $\mathrm{A}$ to $\mathrm{B}$ along three different paths $1$, $2$ and $3$ respectively (as shown) in the gravitational field of a point mass $m$. Find the correct relation between $W_1$, $W_2$ and $W_3$.