According to this http://yourdailygerman.wordpress.com/2013/05/07/meaning-grund/ die Begründung means not so much the reason but more the justification for something.
Agreed, 'justification' seems an exact translation of the term 'Begründung'... however, the alternative suggestion from Duolingo (which implies the use of 'statement') seems wrong to me. Could anybody confirm or reject this assumption?
I'd recommend reading the above link on the meaning of Grund. But in a nutshell, "basis" is the underlying reason for something, while "Begründung"/"justification" is more about the process or action of explaining the underlying reason.
A basis has to exist before some action is taken, but a justification can be created after the action is taken. A justification seeks to explain the basis, but also has the possibility of being incorrect. Whereas a basis can't be incorrect, it simply either a cause for an action or it isn't.
Umm. I think "What ARE the reasonS ?" is better English than "What are the reason."
'was ist' translates to 'what is' not 'what are' which would be 'was sind die Begrundungen'
Kann Mann auch schreiben ''Was ist der Gund?'' oder ''Was ist die Gründung?''
This response comes a year after your comment, so I am certain you will have found the answer yourself since then, but for others who may be interested ...
Begründung (Angabe von Gründen / Giving reasons)
Eine Begründung für etwas angeben/finden/haben
a reason for something
Eine theoretische Begründung für etwas
A theoretical reason for something
Die Mitglieder haben eigene Projekte entwickelt und umgesetzt, zum Beispiel
die Gründung eines Forschungs und Innovationszentrums ...
The members have developed and implemented their own projects, for instance
the foundation of a research and innovation centre ...
Jede Naturkatastrophe hat
Every natural disaster has
Der Grund für das schlechte Wetter ist ein Tiefdruckgebiet
The reason for [or cause of] the bad weather is an area of low pressure.
Begründung is more along the lines of establishing/offering a reason for decisions/actions taken
Gründung refers to the foundation of something
Grund refers to reason/cause, but from a scientific basis - what caused something to happen, as opposed to justifying why something has happened
I hope that helps
To me, what are the grounds, means the same as what is the justification, and seems closer to the German, but I don't know if this is acceptable.