To solve this problem, we need to understand the nature of the substances mentioned in the question and the options.$\newline \bullet$Antivenom injection contains preformed antibodies. These are antibodies that are already formed and are introduced into the body to neutralize toxins, such as those from snake venom.$\newline \bullet$Polio drops, on the other hand, are a form of oral vaccine. They contain attenuated pathogens, which are weakened forms of the virus that cannot cause disease but can stimulate an immune response.$\newline$Now, let's analyze the options:$\newline \bullet$Option 1: Activated pathogens - This is incorrect because vaccines typically use attenuated or inactivated pathogens, not activated ones.$\newline \bullet$Option 2: Harvested antibodies - This is incorrect because polio drops do not contain antibodies; they contain a form of the virus.$\newline \bullet$Option 3: Gamma globulin - This is incorrect in the context of polio drops. Gamma globulin refers to a class of proteins in the blood, which includes antibodies, but polio drops contain the virus, not antibodies.$\newline \bullet$Option 4: Attenuated pathogens - This is correct because polio drops contain attenuated (weakened) forms of the poliovirus to stimulate immunity without causing disease.$\newline$Therefore, the correct answer is Option 4: Attenuated pathogens.