Those questions regarding a 1099-R distribution help determine whether or not the distribution is subject to a 10% premature distribution penalty. It's seems that you passed one of the exceptions to the penalty.
It means separation from the company where you had the 401(k).
See IRS Tax Topic - http://www.irs.gov/taxtopics/tc558.html
Distributions made to you after you separated from service with
your employer if the separation occurred in or after the year you
reached age 55, or distributions made from a qualified governmental
defined benefit plan if you were a qualified public safety employee
(State or local government) who separated from service on or after you
reached age 50.