How did “the irresistible demands of commerce"
influence the building of the bridge?

The correct answer is: People wanted the bridge built because it would be good for business.

Explanation:

In the excerpt, the author clearly states that the people wanted to build a bridge because they considered it would be good for business. We can also conclude that from the following sentence: The irresistible demands of commerce enforced these hard conditions.

As we can notice, this irresistible need of commerce enforced the hard conditions for the construction of the bridge, and people doubted the construction would begin at the earnest.

the answer is both an appeal to ethos and logos (if that's what your question options were)

there is no sentence to look at.