I am still confused about options.Let's say I buy 100,000 IBXOA...

I am still confused about options.

Let's say I buy 100,000 IBXOA tomorrow at 1.4c each.
It will cost me $1,400 tomorrow.

Strike price is 3c.

Let's say I hold my 100,000 options until just before they expire and the IBX price is $0.20.

I want to convert my 100,000 options to shares.

What happens next? Do I pay more $ to convert? If so, how much? Is the end result that I have 100,000 shares in IBX? Other?

I know there was some explanation here and I have tried getting a clear example through Google but I must be a bit slow.... any help to make this clear would be appreciated.