The Free Exercise Clause of the First Amendment protects an individual's right to practice their religion freely. Among the options provided:
A) Permitting slavery - This is incorrect because slavery is not a religious practice and is not protected by the Free Exercise Clause.
B) Firing guns into the air - This is also incorrect as it poses a public safety risk and is not a religious practice.
C) Disobeying traffic laws - This is incorrect, as disobeying traffic laws is not typically justified by religious beliefs.
D) Not attending worship services - This is correct, as individuals have the right to choose not to participate in religious activities without facing discrimination or legal consequences based on their beliefs.
Therefore, the correct response is D: not attending worship services.