A project's critical path is composed of activities $A($variance $0\mathrm{.}33),B($variance $0\mathrm{.}67),C($variance $0\mathrm{.}33),$ and D $($variance $0\mathrm{.}17).$

What is the standard deviation on the critical path?

a$)$ None of them

b$)3\mathrm{.}27$

c$)1\mathrm{.}50$

d$)1\mathrm{.}22$

$$ Bo$$ b$$rak