JEE Math Practice Question

If $$f(x) = [x] - \left[ {{x \over 4}} \right]$$ ,x $$ \in $$ 4 , where [x] denotes the greatest integer function, then

1. A.Both $$\mathop {\lim }\limits_{x \to 4 - } f(x)$$ and $$\mathop {\lim }\limits_{x \to 4 + } f(x)$$ exist but are not equal
2. B.f is continuous at x = 4
3. C.$$\mathop {\lim }\limits_{x \to 4 + } f(x)$$ exists but $$\mathop {\lim }\limits_{x \to 4 - } f(x)$$ does not exist
4. D.$$\mathop {\lim }\limits_{x \to 4 - } f(x)$$ exists but $$\mathop {\lim }\limits_{x \to 4 + } f(x)$$ does not exist