A metal block maintained at constant temperature \(T_C\) receives heat from a hot reservoir at temperature \(T_H\) (where \(T_H > T_C\)) through a cylindrical rod of length \(L\), cross-sectional area \(A\), and thermal conductivity \(k\). To maintain the block at \(T_C\), liquid coolant at an initial temperature \(T_0\) (where \(T_0 < T_C\)) is continuously supplied to the block, where it warms to its boiling temperature \(T_C\) and completely vaporizes at \(T_C\). The coolant has a liquid specific heat capacity \(c_l\) and latent heat of vaporization \(L_v\). Assuming no heat is lost to the surroundings, which of the following expressions represents the required coolant mass flow rate \(\dfrac{\Delta m}{\Delta t}\) to keep the block in thermal equilibrium?