Work is said to be done by a force on a body if           

Explanation option 1, 2

$\underset{\text{S}}{\overset{\text{F}}{\rightleftarrows }}\theta =0$

$\text{W}=\text{FS}\cos \theta =\text{FS}\left(\text{1}\right)=\text{FS}$

$\text{W}=\text{FS}\cos 90$

$\text{W}=\text{FS}\left(0\right)$

$\text{W}=0$

Other than 90 no zero