Answer:
1, overshadowing
Step-by-step explanation:
A compound stimulus consists of a click, which already has 15 units of associative value, and a scent, which has 0 units of associative value. This compound stimulus is then paired with a shock that can support a maximum associative value of 15 units. Following these pairings, the scent will likely have 1 units of associative value, which is a demonstration of overshadowing.