Ann: Quarterly Activities Report and Quarterly Cashflow Report, page-7

I think they know what they've got. It's more a question of scale, markets and marketability, and competition - is it commercially viable?

Pretty much said so in the Q:

The additional option period allows Dominion to undertake a test work program to confirm the marketability of product from the Georgia Lime Project for major regional markets and end-users with planning of the test work program underway.

▪ The decision to undertake the test work program was based on the results of a preliminary marketing investigations that highlighted the sensitivity of factors such as the markets that the Georgia Lime Project may be able to sell its product into, the distance from other limestone producers and the distance from potential customers.

▪ The output from the test work program is a critical component of scoping and technical studies to be undertaken for the Georgia Lime Project and is likely to influence a number of production parameters including the scale of the Project and selection of the preferred processing methodology.

Also note in the 3rd para, scoping and technical studies to be undertaken. So, a way to go yet before a final decision is made on whether to exercise the option.

Or not.