If it says that you have to pick one of those alignment, you have to pick one of those alignments.
It is allowed to be one step away on the scale from the deity's alignment, not from the "allowed alignment" (cake on cake?
![Tongue :P](https://forums.layonara.com/Smileys/default/tongue.gif)
).
The deity you are looking at are most probably having a CE alignment, so, only CE, CN and NE are allowed (effectively, only CN as both others are seriously restricted ones).
In my own opinion, a cleric should have the same alignment as the deity, unless some very strong reason are given.
![Smiley :)](https://forums.layonara.com/Smileys/default/smiley.gif)