Which of these situations would follow the general rule for basis of inherited property?

On August 15, 2018, Bob gave his brother appreciated stock.

Bob's brother died on February 16, 2019, and Bob was his only heir.

Everett died on June 30, 2019. He named his brother Elliott as the beneficiary of his 401(k) plan.

Ronald died on October 16, 2019, leaving his estate to his sister, Sonia.

Eloise died on January 6, 2019, leaving each of her three daughters a share in her IRA.