10 points will be given to whomever answers first, and will be the plz concerned with a case in which a group of students wore black armbands to school in protest of the vietnam war, tinker v. des moines established which of the selections below in regard to the right to free speech?

a. does not apply to government activities
b. extends to public schools and their students
c. does not apply to minors
d. cannot be used for political protest