Fitting a counter top basin

[CaptainJack88]

We've got a wooden countertop and have a basin to go on top of it, however I'm reading various techniques on how to attach it.

From what I can tell, I have 2 options:

A) Cut a hole 45mm wide to accommodate the clicker plug. Silicone the basin to the top and drop in the plug.
Then tighten the nut on the clicker to the underside of the worktop

B) Cut a hole 55mm wide to accommodate the the clicker plug and nut. Silicone the basin to the top, drop the plug in and tighten the nut to the bottom of the basin

Option A seems like the most logical to me as it provides a more secure fastening, but I'm not sure. Any suggestions?

 

[Bosswhite]

Some "trendy" models of counter top basins have a couple of ridges so the basin can sit proud of the worktop or fit in completely in the hole that is cut, this maybe why there are two different sizes for the hole.
I did one like that a few months ago, unfortunately it caused a domestic dispute, the wife wanted it sitting proud of the worktop, the husband wanted it flush,
of course I had to install it by instructions of "SWMBO"
The Husband called me back a couple of months later and I had to fit it Flush with the worktop