How does seeing an object compare with seeing a shadow

So we can see objects by seeing silhouettes. By contrast, shadows are not parts of their objects—we can change a shadow without changing the object (say, by putting another object in between the object and the light source). So we cannot see objects by seeing shadows.

Explanation:

your answer would be a. 12.5 kg

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg