A Property of Borel Subsets of Wiener Space

Wiener measure $m({\lambda}B)$ can behave arbitrarily badly as a function of ${\lambda}$ for Wiener measurable sets B. We show however that $m({\lambda}B)$ is Borel measurable with respect to ${\lambda}$ for any Borel subset B of $C_0$[0, 1].