The method of obtaining oil is D. Tar sands extraction.
Step-by-step explanation:
Surface mining (A) and underground mining (C) are methods used to extract minerals and ores from the earth, but they are not used to obtain oil. Coal mining (B) is a method used to extract coal from the earth, and while coal is often found in the same geological formations as oil, the two resources require different methods of extraction.
Tar sands extraction (D) is a method used to extract oil from deposits of bitumen, a heavy and viscous form of oil mixed with sand, clay, and water.