What was at issue in minersville school district v. gobitis?

The issue in this Supreme Court case was mainly about the first amendment and the freedom of religion. It was brought into question about whether or not a school could force a child to salute the American Flag and recite the Pledge of Allegiance when the child had objections to do it on religious grorund. In this case it was a Jehovah Witness, but the Supreme Court ruled that a public school could force a child, despite their religion, to say the Pledge.

However, this decision didn't last long and was overturned only a few years later. 

The answer to your question would be b

B. marbury v madison