Read the following passage and solve the questions based on it.
There are six classes to be held everyday by six different teachers—A, B, C, D, E, and F in a school. Three of these classes will take place in the morning session before the lunch break whereas the other three classes will be held in the afternoon session after the lunch break.
The scheme of the classes should follow the following restrictions
Class by B should be immediately before the class by C and their presentations cannot be separated by the lunch break.
Class by D must be either the first or the last class.
In case class by F and class by E are the fifth and sixth classes of the day respectively, then which of the following must be true?