Translation:It is difficult to get a promotion.
I don't see where the indefinite article is expressed in this sentence. Would that not be "een promotie"? I just said promotion,which was marked incorrect.
I suppose they only use 'promotie' as a mass noun, not a count noun. In English, we do both. I simply answered "It's hard to get promoted" which was accepted. ;)
It is difficult to get promotion/It is difficult to get a promotion.
In UK English the first translation (which I would regard as the correct one here) is a generalisation in the sense that no promotion is ever easy. The second one refers to a particular promotion, or a particular employer, implying that other promotions are easy but this one is difficult.
For example, you might say "It is easy to get promotion in the administrative grades but a promotion to managerial grade is difficult"