Required minimum distribution

Hi,  I tried searching the forum but haven't been able to find a direct answer to my question below.

 

I have three accounts from three different sources.  Account one is my 401K from my previous employer.  Account two is an IRA through my bank and account three is an annuity from an insurance company.   Do I need to withdraw an RMD from each since they are from various companies or can I withdraw all my RMD from just one account.   I thought I could withdraw from just one and I went ahead withdrew the total amount from my lowest account.  Now I'm being told otherwise and if I do need to draw from each account, I need to do it now while I'm within my allotted time frame.   I would like to get a correct answer before I file my taxes.

 

Thanks for any help you can provide.

 

Steve