D. rift valleys.
Trenches occur at convergent oceanic plates; fossils are extremely old bones, bodies, or footprints, which have gotten so old the intervening years have turned them into rock; U-shaped valleys are valleys which are shaped like the letter U, and are usually formed by glaciers, which tend not to occur underwater very often.
Answer:OB.
San Francisco Earthquake of 1906
The tropical rainforest is a biome with a constant temperature and a high rainfall. The level of humidity and density of the vegetation give the ecosystem a unique water and nutrient cycle. Rainforests around the world are threatened by human expansion.
The answer is mineral deposits