For \( x\in \mathbb{R} \), two real valued functions \( f(x) \) and \( g(x) \) are such that, \( g(x)=\sqrt{x}+1 \) and \( f\circ g(x)=x+3-\sqrt{x} \). Then \( f(0) \) is equal to:
\( 1 \)
\( 5 \)
\( 0 \)
\( -3 \)