question_answer

The range of the function \[f(x)\,={{6}^{x}}+{{3}^{x}}+{{6}^{-x}}+\]\[{{3}^{-x}}+2\] is

A)  \[[-2,\infty )\]                

B)  \[(-2,\infty )\]       

C)  \[(6,\infty )\]                 

D)  \[[6,\infty )\]