What did triumphal arch represent to the romans

C) Triumphs in ancient Rome were granted to an especially successful general. They were not awarded for single battles but for a major campaign victory. It was the only occasion on which a general could bring troops into the City of Rome. The general would ride in a chariot, his most important captives would be displayed in cages and sometimes strangled at the end of the display, the best of the war booty would be on display, and tableau would show significant scenes from the campaign. 
In effect the triumphal arch was a recreation of this in stone as a permanent memorial.

Idont think that you can i mean there are no more options to change

Guernica is the right answer