Ian retired in June of 2013 at the age of 69 (he turned 70 in August of 2013). Ian's retirement account was valued at $490,000 at the end of 2012 and $500,000 at the end of 2013. What is Ian's required minimum distribution for 2014 under each of the following alternative scenarios?
a. Ian's retirement account is a traditional 401(k) account.
b. Ian's retirement account is a Roth 401(k) account.
c. Ian's retirement account is a traditional IRA.
d. Ian's retirement account is a Roth IRA.