According to the Rescorla-Wagner Model,the UCS Preexposure Effect Is Due

According to the Rescorla-Wagner model,the UCS preexposure effect is due to ______.

A) conditioning contextual cues during preexposure blocks conditioning to the conditioned stimulus
B) the total amount of associative strength supported by the unconditioned stimulus declines with preexposure
C) the surprise value of the unconditioned stimulus is weakened by preexposure
D) the animal is less likely to attend to the conditioned stimulus after unconditioned stimulus preexposure