The correct answer is D. All of the above.
Term contracts, term tenders, and monthly tenders are all common methods used to import crude oil and petroleum from national oil companies of producer countries.
Term contracts are long-term agreements between an oil company and a producer country to purchase a certain amount of oil at a fixed price over a period of time. Term contracts are often used by oil companies to secure a steady supply of oil at a predictable price.
Term tenders are similar to term contracts, but they are shorter-term agreements. Term tenders are often used by oil companies to purchase oil for specific projects or to meet short-term needs.
Monthly tenders are the most common type of tender used to import crude oil and petroleum. Monthly tenders are open to all oil companies and are typically used to purchase oil for spot market sales.
The type of tender used to import crude oil and petroleum will vary depending on the needs of the oil company and the producer country.