If $a\in R$ and the equation $-3 (x-[x])^2 + 2(x-[x])+a^2 = 0$, (where $[x]$ denotes the greatest integer $\leq x$) has no integral solution, then all possible values lie in the interval:

Question

$\begin{array}{1 1}(-1,0) \cup (0,1) \\ (1,2) \\ (-2,-1) \\ (-\infty, -2) \cup (2, \infty)\end{array}$