In "Sonic the Hedgehog 2" for the Sega Genesis, what do you input in the sound test screen to access the secret level select?

Explanation

To unlock the secret level select in Sonic the Hedgehog 2 on Sega Genesis, players need to input the correct code during the game's sound test mode. The code is entered by highlighting the sound "SEG" and then pressing up, down, left, right, up, down, left, right, A, B, A, B, A, B, C, D, Start. This combination spells out "SEGA" backwards, followed by the letters "RMC", which stand for the lead programmer for the game, Yuji Naka. If entered correctly, players will be taken to a secret level selection screen where they can choose from various levels not accessible through normal play.