Why did the Romans choose the arch as a symbol of triumph? It may be because the arch represented the triumph of Roman engineering over the most difficult structural problems. The architects of ancient Egypt and Greece knew about the arch, but their architecture was mostly trabeated, based on vertical columns spanned by horizontal, flat beams. The Romans didn't invent the arch; they adopted the form from the architecture of the Etruscans, the people who ruled Italy before the beginning of the Roman Republic in the sixth century B.C. But to their credit, the Romans perfected the techniques of arch construction, making Roman architecture different from anything that came before it. It was because they understood the techniques of arch construction that Roman architects would later be able to develop even more complicated structures, such as the vault and the dome.

Which is the best summary of paragraph 3?
a. An understanding of arch construction led to advancements in Roman architecture.
b. The rounded arch, first built by the Romans, was stronger than the flat arches built in Egypt and Greece.
c. The arch has always represented the strength and creativity of Roman engineering.