If f of x is equal to 3 x plus 2 and g of x is equal to x squared plus 1 , which expression is equivalent to open paren f circ g close paren times x ?
A
open paren 3 x plus 2 close paren squared plus 1B
3 times open paren x squared plus 1 close paren plus 2C
3 x squared plus 1 plus 2D
open paren 3 x plus 2 close paren times open paren x squared plus 1 close paren