The drug stimulates a chemical reaction
The correct answer is biological.
Biology deals with the inner workings of our body - so, if something is the result of hormones and other physiological processes, then it will definitely be related to biology. The other options have more to do with the environment, rather than with the body itself.
Obesity is when your BMI is overweight or above average
Yes
Workout in the gym and eat more healthy foods
Gyms and parks
Rigorous amount/portions of unhealthy foods on a daily basis
Gyms should be open to all and should be free to be used so that people can be encouraged to work out more, Low price for healthy foods and set up fun community building activities that includes physical activities as well