Catriona's Gassy Gadgets Inc. stock returns for the past $5$ years were $8\%,2\%,-14\%,3\%,$ and $7\%.$ What is the historical sample standard deviation?

a$\mathrm{.}0\mathrm{.}012$

b$\mathrm{.}0\mathrm{.}0079$

c$\mathrm{.}0\mathrm{.}070$

d$\mathrm{.}0\mathrm{.}0887$