The required probability that a two$-$stage rocket will perform successfully is $0\mathrm{.}97.$ The reliability

for the first stage is $0\mathrm{.}99.$ The reliabilities of the two stages are independent. What must be the

reliability for the second stage?

a$-0\mathrm{.}90$

b$-0\mathrm{.}95$

c$-0\mathrm{.}97$

d$-0\mathrm{.}98$