Answer:
a.The project has been approved and it has been proved necessary.
b. They often choose the cheapest budget and do not forecast any problems in to make the project more viable.
Step-by-step explanation:
a.There's an extensive process to approve a project like this, since it has so many filters before being approved, canceling it would be saying these filters failed. These filters exist to prove that these projects are necessary and if they're necessary they need to be done, no matter the cost.
b. THe people in charge of setting these projects going often choose the cheapest options to make the projects viable, when doing so the cost will eventually rise and, when the government has already approved it they will continue to spend money on the project.