The correct option is B 234 monsters can be divided into 9 groups
Total monsters =234
Check whether 234 can be divided into 5 groups.
Any number ending with the digit 0 or 5 is divisible by 5.
Last digit of the 234 is 3. 234 is not divisible by 5. Thus, 234 monsters can not be divided into 5 groups
Check whether 234 can be divided into 9 groups.
If the sum of the digits of a given number is divisible by 9, then the number is also divisible by 9.
The sum of all the digits of 234 is 2+3+4=9, which is divisible by 9. Thus, 234 monsters can be divided into 9 groups
Check whether 234 can be divided into 10 groups.
The number whose last digit is zero is divisible by 10.
Last digit of 234 is 3.234 is not divisible by 10. Thus, 234 monsters cannot be divided into 10 groups.
So, 234 can be divided into 9 groups only.
Hence, statement B is correct.