Final answer:
Surface mining includes techniques like strip mining, dredging, and placer mining; all of which are methods used to extract minerals found near the earth's surface.
Thus, the correct option is d.
Step-by-step explanation:
The techniques of surface mining include strip mining, dredging, and placer mining. These methods are used to extract minerals near the earth's surface.
Strip mining involves the removal of soil and rock to access mineral deposits. Dredging involves scooping out minerals from the bottom of water bodies. Placer mining involves searching for minerals in river sediments.
Therefore, the correct answer to the question is d) All of the above.