Which product design below has the higher system reliability?

$\mathrm{.}98\mathrm{.}99\mathrm{.}985$

R$1$ R$2$ R$3$

$\mathrm{.}98\mathrm{.}98\mathrm{.}98$

R$1$ R$2$ R$3$

A B

$\mathrm{.}95\mathrm{.}95$