One Option with many products

Hi,

I am running IC version 4.7.2, and I want to use the following feature.
I have about 1000 products in my database and I want to give them
options. But there are ranges of products that carry the same options.
You can imagine that I have 100 different t-shirts, but they all come in
size M, L, and XL. I entered some goods, but as you might imagine I was
getting fed up with entering all these options manually. I have searched
the archive, but I cannot find any information on how to accomplish
this. Does anyone know how to do this. If so, could you give some tips
on how to do this.

Thank you

Regards

Guy Soudant