Fill in the blank with the correct option.
The teacher believed that the student’s sudden lack of interest in class was an ..........., as he had always been enthusiastic and attentive.
Rearrange the parts to form a coherent sentence:
A) is no longer a privilege
B) that only the elite enjoy
C) quality education
D) in the modern world
What comes next in the series?
\(2, 6, 12, 20, 30, \ ?\)