Выберите правильный вариант и объяснить почему он правильный

1. She said that it was going to be a wonderful party.
A. "It was going to be a wonderful party"
B. "It's going to be a wonderful party"
2. He said the bus might be a little late that day.
A. "The bus was a little late today"
B. "The bus might be a little late today"
3. She told him that he should study harder
A. "You should study harder"
B. "You should have studied harder"
4. He said that the fire had done a lot of damage to the building.
A. "The fire had done a lot of damage to the building.
B. "The fire has done a lot of damage to the building.
5. He said that Michael was the best student he had ever taught.
A. "Michael is the best student I have ever taught.
B. "Michael was the best student I have ever taught.