Which reaction is a single replacement reaction?

2H202 → 2H20 + 02
• 2H2 + 02 → 2H20
• KOH + HCI → KCI + H20
• Cu + 2AgNO3 → 2Ag + Cu(NO3)2

The reaction "Cu + 2AgNO3 → 2Ag + Cu(NO3)2" is a single replacement reaction.