Question: how to connect external monitor to macbook pro retina?
Answer: Specifically, Apple provides two options to connect an external monitor to the Retina Display MacBook -- the Apple USB-C Digital AV Multiport Adapter (MJ1K2AM/A), which has an HDMI port, and the Apple USB-C VGA Multiport Adapter (MJ1L2AM/A), which has an old school VGA port.