Correct answer is (a) Better takeoff and landing performance
To explain: Supercritical airfoils work efficiently even in the transonic regime. It’s unique geometry of large leading edge, flatter top surface and cusp shape at the bottom aft section all result in high lift. This leads to very good take-off and landing performance as during this flight regime, higher lift is required. For this reason, cargo flights make use of supercritical wings.