Unit Promotion Calculations

[Deity Dude]

I don't know if this has been covered here but I can't find it in the manual.

Do Multiple Promotions reslt in the final promotion value, the additive value or the cummulative value.

For example what is the final value of an archer in a city with City Garrison I and City Garrison II:

is it
a ) final promotion value 5.625 = 4.5*1.25
b ) additive value 6.525 = 4.5*1(.2 + .25)
c ) cummulative value 6.750 = 4.5*1.2*1.25

I suspect it is c) but cant find it anywhere.

[Tieom]

It's the additive value.

Infantry (20) w/ City Defender I and II:
=20 * (1 + 0.2 + 0.25) = 29

You can see this if you hold your mouse over the name/picture of the selected unit... It will say "+45% City Defense."