The Roman government wanting to spend money building new roads would require approval from:
- The Senate
In ancient Rome, the Senate held significant power when it came to financial matters and public spending. The Senate was responsible for approving or rejecting proposals related to large expenditures like the construction of new infrastructure such as roads. Their approval was crucial in allocating funds for various public projects to ensure they were in the best interest of the Roman state.
While the other options mentioned in the question, such as the assembly, the consuls, and the plebeians, played important roles in Roman governance, when it specifically came to approving funds for major projects like building new roads, the Senate held the authority to make such decisions.