According to the lemon test, wich of the following would be legal

A private religious school uses public funds to hire a religion teacher
A public high school requires students to stand for the prayer before a football game
A private religious school uses public funds to hire a cafeteria worker
A public high school forbids teaches from purchasing lottery tickets

According to the Lemon test, the only option that would potentially be legal is "A private religious school using public funds to hire a cafeteria worker."

The Lemon test is a three-pronged test established by the Supreme Court in Lemon v. Kurtzman (1971) to determine the constitutionality of government action concerning religion. The three prongs are as follows:

1. The government's action must have a secular legislative purpose.
2. The primary effect of the government's action must neither advance nor inhibit religion.
3. The government's action must not result in excessive entanglement between government and religion.

Based on these prongs, hiring a religion teacher in a private religious school using public funds or requiring students to stand for prayer at a public high school would likely violate the separation of church and state constitutional principles. Additionally, forbidding teachers from purchasing lottery tickets in a public high school would likely be unrelated to religion and therefore not applicable to the Lemon test.