A small horizontal axis wind turbine (HAWT) is designed to deliver 2 kW shaft power at a steady wind speed of \(7\ \text{m.s}^{-1}\). The HAWT operates with an aerodynamic power coefficient of 0.36, a drivetrain efficiency of 0.90, and an air density of \(1.225\ \text{kg.m}^{-3}\). Neglecting other losses, the required rotor diameter is \(X\) m. When the wind speed drops to \(6\ \text{m.s}^{-1}\), the shaft power is \(Y\) kW. Identify the nearest correct option for the \(X\) and \(Y\) combination (take \(\pi = 3.14\))