Which of the following transgenic animals are utilized to test the safety of polio vaccines before their administration on humans?

Transgenic mice

The correct answer is Option (3) -  Transgenic mice

Transgenic mice are genetically modified mice that have specific genes inserted into their DNA to mimic certain aspects of human biology. They have become valuable tools in scientific research, including vaccine safety testing. When it comes to testing the safety of vaccines before they are used on humans, transgenic mice offer several advantages over traditional testing methods that involve monkeys.

Transgenic mice can be engineered to express certain human genes relevant to vaccine safety, making them more physiologically similar to humans in specific aspects. This enables researchers to better understand how vaccines may interact with human immune systems, improving the accuracy of safety assessments.