Interview location not based on state of residence

[gur12327]

Hello,

My parents have applied for visitor visa in Delhi consulate (not based on state of residence)
Because delhi is closer to their place.

If in interview, they ask why delhi not mumbai consulate.
what could be the answer

--We thought we could apply anywhere, and Delhi is closer to our place
OR
-- date and time in mumbai consulate was not suiting us.

becuase I have seen , visa rejected because of this

Thanks