设函数\(f(x)=a\sin ωx+b\cos ωx(ω > 0)\)在区间\([ \dfrac {π}{6}, \dfrac {π}{2}]\)上单调,且\(f( \dfrac {π}{2})=f( \dfrac {2π}{3})=-f( \dfrac {π}{6})\),当\(x= \dfrac {π}{12}\)时,\(f(x)\)取到最大值\(4\),若将函数\(f(x)\)的图象上各点的横坐标伸长为原来的\(2\)倍得到函数\(g(x)\)的图象,则函数\(y=g(x)- \sqrt {x+ \dfrac {π}{3}}\)零点的个数为\((\:\:\:\:)\)
A.\(4\)
B.\(5\) C.\(6\) D.\(7\)