Answer:
B) 1st Extinction (CS alone)
Step-by-step explanation:
Unconditioned stimulus: food
Neutral/Conditional Stimulus: tone
Unconditioned Response: salivation
Conditioned response: salivation in response to tone
With the 1st Extinction, the conditional stimulus (CS), tone, is presented alone without the food for the first time. Many may choose A (Acquisition (NS + US), howver it is incorrect because the food is still present (US), which is not what the question is asking. Rather, we seek to determine the first instance in which the tone is repeated but food is not present. As such, B) 1st Extinction (CS alone) is the correct answer.