$(3)[10$ points$]F(x)={\displaystyle \underset{0}{\overset{x}{}}}sin(t)dt$ for $0x2.F$ is increasing only in the open int$$rval$($s$)$

$($A$)(\frac{}{2},).$

$($B$)(0,\frac{}{4}),(\frac{5}{4},2).$

$($C$)(0,).$

$($D$)(\frac{3}{4},).$

Answer: