Questions from the DS-160 form for B1/B2 visa

[bigbangtheory]

So my parents are eligible for dropbox facility for their B1/B2 visa renewal. Their last 10 year visa expired on Apr. 2018. During that time (2008 - 2018), they had visited me in the US four times. I (son) was completing their DS-160 from US on their behalf, and had couple of questions from that form.

1. Should I select B1/B2 (Business & Tourism) or just B2 (Tourism/Medical Treatment) in the visa category? I'm asking this because there is also a question later in the form which asks "Are you applying for the same type of visa?". I checked their last visa and it says B1/B2 under Type/Class and R under Visa . They will just be visiting me for pleasure and tourism and not for any business, so I'm a bit confused as to what to choose. Their previous visa was also used for pleasure and tourism and not for any business. If I choose B2, then should I answer "Yes" to the question "Are you applying for the same type of visa?" (as their last visa was B1/B2)

2. On the question of "Person paying for the trip", I selected "Self" as my parents will be using their own funds to travel to the US. Of course once they are here, they will stay with me and their expense with food and other basic amenities will be covered by me. So is "Self" the correct option to choose? My father is also retired but they are well off in India with a good pension and a house. My mother was never employed and is a homemaker. So does putting "Self" have any affect on the outcome despite my father being retired? Essentially, what I mean is whether choosing "Self" is too ambitious for a retired individual, and whether that would trigger an interview call from the consulate to check their financial status. Or should I choose myself (son) as the person paying for the trip as they will stay with me? 

Thanks.