Write the expression sin(tan^-1)x) as an algebraic expression in x (without trig or inverse trig functions).

A. (sqrt (1+x^2))/ (x)
B. (1) / (sqrt (1+x^2))
C. (x) / (sqrt (1-x^2))
D. (x) / (sqrt (1+x^2))
E. (1) / (sqrt (1-x^2))