The correct option is C 1, 10
Let the number be x.
So, the other number will be x + 9
Given: Sum of two numbers = 11
Therefore, x + x + 9 = 11
⇒ 2x + 9 = 11
If x = 1,
2x+9=2×1+9=11 (LHS = RHS)
Therefore, x = 1 holds good for the equation.
Therefore, one of the numbers will be 1.
And, the other number = x + 9 = 1 + 9 = 10