a biomedical sensor has the following static characteristic

$Z=\frac{B}{A+C},$ the percentage uncertainty $($deltaZ$/$Z$)\%,$ for this sensor$,$ given $B=100+-0\mathrm{.}2,A=70+-\mathrm{.}07$ and $C=30+-\mathrm{.}03,$ is equal

to$?$

a$.+-\mathrm{.}02$

b$.+-\mathrm{.}2$

c$.+-\mathrm{.}03$

d$.+.003$

e$.$ none of the previous