the phasor transform of the following wave is

$v=170cos(377t-40)$

Select one:

a$.$

$\frac{85}{{?}_{-}}40$

b$.$

$\frac{170}{{?}_{-}}40$

c$.$

$\frac{170}{{?}_{40}}$

d$.$

$\frac{85}{{?}_{40}}$