Given the numbers 1,3 and 9
For Option A
Adding 1 to any of the numbers will make a composite number
1+1=2 which is not coposite
3+1=4 = 2x2 which is composite
9+1=10 = 2x5 composite
Since one of them is not composite
Therefore option A is wrong
For Option B
Adding 2 to any of the numbers will make a prime number.
1+2=3 which is a prime number
3+2=5 which is a prime number
9+2=11 which is a prime number
Since all of them are prime numbers
Therefore, Option B is correct
For Option C
3 and 9 are prime numbers.
9=3x3 an