Had watched your lecture on this topic Current ratio includes inventory so cost of inventory is added or cost of inventory plus cost incurred in making inventory ready to sale as goods is added ?
The current ratio is calculated using the figure for inventory in the Statement of Financial Position and this is calculated as per the rules you will have covered in Paper FA (was F3) or at university if you were exempt from that exam.
It is the cost of the inventory, which is the full production cost if they are making their own goods (or the purchase price if they are buying the goods from another supplier).