Rewrite the Statement Using Mathematical Symbols $k$ And $y$ Is a Proper Subset Of

Rewrite the statement using mathematical symbols.
-The set consisting of the elements $k$ and $y$ is a proper subset of $\{ k , b , e , y , u \}$ .

A) $\{ \mathrm { k } , \mathrm { y } \} \subseteq \{ \mathrm { k } , \mathrm { b } , \mathrm { e } , \mathrm { y } , \mathrm { u } \}$
B) $\{ \mathrm { k } , \mathrm { y } \} \subset \{ \mathrm { k } , \mathrm { b } , \mathrm { e } , \mathrm { y } , \mathrm { u } \}$
C) $\{ k , y \} \in \{ k , b , e , y , u \}$
D) $\{ k , y \} \sim \{ k , b , e , y , u \}$