Translation:His bringing up
Is 'his upbringing' also a valid translation, or does that mean something slightly different?
They mean the same thing in essence, although there is a separate noun for 'upbringing, nurture' - magwraeth.
However, this phrase on its own is is not very useful, so it was deleted from the course during beta testing. It is now a zombie, as a system-wide Duolingo bug means that it is still being shown to learners.