It is given that 5% of the students that were in the honours society met with the congresswoman.
It is also known that 12 students met the congresswoman.
Let the total number of students in the honours society be x.
So it follows:
[tex]\begin{gathered} 5\text{ percent of x=12} \\ \frac{5x}{100}=12 \\ x=\frac{1200}{5} \\ x=240 \end{gathered}[/tex]Hence there are 240 students in the honours society.
Option C is correct.