A parent passed away in 2020 and bequeathed me a Muni mutual fund. In order to liquidate the funds the bank required me to setup an account and transfer the assets.

I am now receiving a 1099-B from the bank, showing the parent's original cost basis, therefore increasing the taxable net.   I liquidated the fund immediately after transferring to the my account, so had no holding period. I believe I should select the option "Some or all of the proceeds from this sale do not belong to me" and leave the adjustment option blank, but would appreciate guidance from the community. Thanks in advance!