Answer:
it generates most of the income of the country
Step-by-step explanation:
The oil is the most important natural resource of Iran. The reason for that is that the oil is what brings in the majority of the income of this country, thus the economy it heavily dependent on it. Also, the oil is the most used natural resource, and Iran has plenty of it, so having it as their own natural resources means that they do not have to spend on it, but instead their industry can function on their own natural resources which is significantly cheaper. This is bad for any economy though, because heavy dependence on only one product usually creates a lot of problems, especially if the price or demand for it drops.