JEE Math Practice Question

The real valued function $$f(x) = {{\cos e{c^{ - 1}}x} \over {\sqrt {x - [x]} }}$$, where [x] denotes the greatest integer less than or equal to x, is defined for all x belonging to :

1. A.all real except integers
2. B.all non-integers except the interval [ $$-$$1, 1 ]
3. C.all integers except 0, $$-$$1, 1
4. D.all real except the interval [ $$-$$1, 1 ]