Answer: Option 'c' is correct.
Step-by-step explanation:
Let the number of children be 'c'.
According to question,
"There are 9 more children than parents in a room.
Let the number of parents would be 'p'.
According to question, it becomes,

As there are total 25 people in the room = 25
So, it becomes,

Hence, there are 17 children and 17-9 = 8 parents.
Therefore, option 'c' is correct.