The COP of the refrigerator will be

Question

In the figure shown below, E is the heat engine with efficiency of 0.4 and R is the refrigerator. If Q₂ + Q₄ = 3Q₁, the COP of the refrigerator will be

(a) 3.0                                   (b) 4.5

(c) 5.0                                    (d) 5.5