Solution
= Solution
{c}
If $A\subseteq E$ and $E$ is a <null set>, every interval cover of $E$ also covers $A$. Thus <monotonicity of Lebesgue outer measure> gives $0\leq m^*(A)\leq m^*(E)=0$. Hence \b[every subset of a null set is null], and in particular is <Lebesgue measurable>.