Basis for calculating RMD for Inherited IRA ?

Hi, Mom died in December 2023, she did take her 2023  RMD prior to her death.  Today, Feb 8, 2024, her IRA account was transferred into my name, I'm just an ordinary beneficiary.    I know I have to abide by the 10 yr rule, I am 76 years old, so I need to take an RMD this year.   Question:  when I use the RMD calculator, what amount/date do I use as the basis?  The value of the account in December , the date of Mom's death?  Or December 31st?  Or today's date when the account was actually transferred to me?  

Thank you !