Why does Turbotax need to know the cost basis and purchase date of inherited stock that i have donated to a charity?

I inherited some stock and do not know when it was purchased or what the purchase price was.

I donated the stock to a charity.  Why does TurboTax ask me what the purchase price was and the date it was bought?

That shouldn't matter since I gave it all away to charity, right?

This has stopped me dead in my tracks on preparing my taxes for 2018.

Thanks in advance!