In Mark 14, to whom did Judas Iscariot go in order to betray Jesus?

Answer: The chief priests

Judas went to the chief priests, who were delighted and promised to give him money.

“Then Judas Iscariot, one of the Twelve, went to the chief priests to betray Jesus to them. They were delighted to hear this, and they promised to give him money. So Judas began to look for an opportunity to betray Jesus.”— Mark 14:10-11 (BSB)