The scenario that is allowed under the free-exercise clause is when a parent leads a prayer in a public park, as it aligns with the right to practice religion freely. Other scenarios, such as a teacher giving out crosses at school, raise constitutional issues. The free-exercise clause protects individual religious expression, especially in public spaces. ;
The scenario allowed under the free-exercise clause is when a parent leads a prayer in a public park, as it supports the right to practice religion freely. The other options either violate the establishment clause or raise ethical concerns. Therefore, the correct answer is option A.
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