Explanation:

- Peak and End: This is not about probability. It’s a bias where people judge an experience based on how they felt at its most intense point and at its end.

- Scarcity Heuristic: This is when something seems more valuable if it’s scarce. It’s not specifically about making probability-based decisions.

- Working Backward: This is a problem-solving strategy, starting from the desired goal and working steps back to the present.

- Base Rate : This is the mental shortcut (heuristic) that uses general information about probability—the “base rate”—when making a decision.

- Affect as information: This is when people use their feelings as a basis for decision making, not directly about probability.

Correct answer: Option 4, Base Rate.