When Jesus and the apostles come down from the mountain they discover the remaining apostles disputing with the teachers of the law. About what are they disputing?

The boy and the demon

Explanation: The argument was about why the Disciples were unable to heal the boy possessed by the Evil spirit, when Jesus and his disciples came down from the mounted he saw the crowd and asked why the argument, that was why the boy's father explained the boy's situation to Jesus and requested him to heal and deliver the boy of the demonic possession, finally Jesus healed him of the Demonic attack. This account is recorded in Mark 9:14-29.

Answer:The boy with a demon

Explanation:

This is a scripture found in Mark 9:14 - 17 NIV Bible quote

Jesus Heals a Demon-Possessed Boy

14When they returned to the other disciples, they saw a large crowd surrounding them, and some teachers of religious law were arguing with them. 15When the crowd saw Jesus, they were overwhelmed with awe, and they ran to greet him.

16"What is all this arguing about?" Jesus asked.

17One of the men in the crowd spoke up and said, "Teacher, I brought my son so you could heal him. He is possessed by an evil spirit that won't let him talk. Mark 9:14-17

The man had brought his son to be healed from a demonic possession but apparently the apostles couldn't do it, Jesus says because of their little faith.

Jesus however was able to rebuke the demon in verse 25 by commanding it to leave the boy and it is said that demon actual screamed and left the boy. When everyone thought the boy was dead he woke him up and let him stood on his feet and the boy was healed.