Question

The Warren Court ruled that official prayer in public schools is unconstitutional because it violates
the right to criticize the government.
the clause barring government from establishing religion.
a right not explicitly named in the Constitution.
the right of students to assemble peacefully.

Answer 1

the clause barring government from establishing religion.

In Engel v. Vitale (1962) the Warren Court held that official school-sponsored prayer violated the First Amendment's Establishment Clause (applied to the states via the Fourteenth Amendment).