If $X=\{a,b,c,d\}$ and $Y=\{f,b,d,g\}$,find (i) $X-Y$

Question

$\begin{array}{1 1}(A)\;\{a,b,c,d\}&(B)\;\{f,b,d,g\}\\(C)\;\phi&(D)\;\{a,c\}\end{array}$