when is the earliest I can apply for British Citizenship?

[hungolad]

Hi there, I need some clarification on the following as I am confused reading different threads.

I am an EU citizen residing in the UK since 09/2007. I have been exercising EU Treaty rights since 10/2009. I applied for a PR card 11/2014 which was approved and received a month later in 12/2014.

When is the earliest I can apply for naturalisation as a British Citizen?

1) Can I apply for citizenship straight away as I have been a resident for more than 7 years now?
2) or only after 12 months in 12/2015 after PR was issued/approved?
3) or 12 months after I claimed 5 years of exercising treaty rights (5+1 years) ie. 10/2015?

Many thanks for your kind help.