After Arthur was bitten by a German Shepherd, he feared all dogs. In terms of classical conditioning, Arthur's fear of all dogs illustrates:

The answer is 102.86

The used coins.. .

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.