Entrepreneur Extension- Genuine Entrepreneur Test – Extensio

Dear Immigration team board Members,

I have previously received loads of advice when I applied for my initial application. I would say that was really helpful. I am preparing my self for an extension so would appreciate your advice. I have received my initial entrepreneur visa in Dec 2013.

I have noticed the following Genuine Entrepreneur Test – Extension Application section. I had few queries regarding the same.
1. the credibility of your business activity in the UK - How to prove that?
2. the viability and credibility of the source of the money - I have invested my own money. So I have paid tax on the money and then invested it in the business - Is that ok?

I would appreciate your help and advice.

Thanks in advance.
Soni