401k plan beneficiary RMD

A participant passed away shortly before her RMD age.  Her spouse is the beneficiary and he is beyond age 72.

He does not want to take distribution of the account balance and prefers to leave it in the plan. 

(1)  Can he leave the balance in the plan indefinitly?

(2) He must begin taking RMDs from the plan; is this based on his DOB alone or does the deceased spouse's DOB factor into this as well?

Thank you