JEE Main 2021 Mathematics question

The real valued function , where [x] denotes the greatest integer less than or equal to x, is defined for all x belonging to :

• (A)all reals except integers
• (B)all non-integers except the interval [–1,1]
• (C)all integers except 0,–1,1
• (D)all reals except the Interval [–1,1]Correct