**Concept: The question tests on the basics of fractions.**

**Solution:**

The expression can be defined if the denominator is defined

- a should not 2 if x is -2 (else the denominator would be 0 leading to an undefined value of the expression)
- a should not be less than 2 else at x=-2 the value of a + x or a-2 will turn negative leading to an undefined denominator and hence an undefined fraction.

Thus the expression is not defined for a<= 2

St (1) If a = 5 it is > 2 and hence YES is the answer derived for the question stem**. **

**(Sufficient)**

St (2) If b =6 we have the numerator as -2 + 6 =4 but we know nothing of the denominator. Hence (**Insufficient).**

Hence **option (A)**