Looking at the opponent's pattern (rock, scissors, rock), there seems to be a tendency to return to rock after playing scissors. Since they played rock in round 3, they might be starting their pattern again with scissors for round 4. However, given they're a "low" difficulty opponent, they might stick with rock as it's their most frequently played move. Choosing paper gives me a good chance to win if they play rock again, while diversifying my own choices to be less predictable.