Are proceeds from inherited stock exchange to cash taxable? We inherited company A stock. Company B purchased company A and exchanged A stock for cash. Is cash taxable?

Our brokerage  sent a 1099-B with this as a line item making it seem like a stock sale.  Since it was inherited stock to begin with we're not sure of tax liability.  We did not choose to have the exchange , it was part of the company takeover. Where do we  enter on 1040?