Answer :

Handwashing is a highly effective method to decrease the spread of germs. According to the data provided, handwashing can decrease the spread of germs in any environment by a significant percentage. Let’s analyze the provided options to determine the correct answer.

- Option a suggests that handwashing can decrease the spread of germs by 65%.
- Option b suggests a decrease of 50%.
- Option c suggests a decrease of 35%.
- Option d suggests a decrease of 15%.

Given the information, the correct percentage by which handwashing can decrease the spread of germs in any environment is:

65%

So, the correct answer is:

a. 65%