Which red double-decker vehicle, with an open rear platform, was the standard design for the capital's public buses from the 1950s?

• A Routemaster ✓
• B Bendy bus
• C Optare Solo
• D Dennis Dart

The Routemaster, designed by A.A. Durrant and entering service in 1956, became a cultural icon; the open platform allowed passengers to hop on and off between stops.