Father is accepted on one of the alternate translations.
I think this is just one of those sentences they're going to be playing catch-up with for a very long time since there are a dozen ways I can think to say this in English which are all equally valid translations for the Russian sentence given.
Really wish the main English translation wasn't such awful English though.
"Dad has neither a duck nor a cat" is still not accepted as of 30.08.2017.
DL could learn a bit from Shakespeare. Hamlet, Act I, Scene 3 (Polonius to Laertes): "Neither a borrower nor a lender be; for loan oft loses both itself and friend."
As nearly every sixth or seventh grader is taught in middle school, the article "a" is not optional, although its omission is frequently forgiven.
Yes - a very typical English expression of this is "Dad has neither ducks nor cats" - no articles, with plurals. Where I come from, most people wouldn't be able to tell you afterwards if I said, "Dad doesn't have a duck or a cat" or what I said - they are just interchangeable. The developers here are trying to maintain a distinction in English which may be significant in Russian, but since it is not in English, I am on the side of this argument that it should be accepted.
The issue is that the English translation lacks the indefinite article twice: Dad has neither a duck nor a cat, but the Russian sentence here doesn't have that awkwardness. In case you are suffering from a cultural shock: In countries outside of the USA, it's pretty common to have large populations in the rural areas. They often have small farms. On such farms, it's common to have ducks and cats. Ducks lay eggs and provide meat, cats hunt down pest. ;P