The correct answer is option 1, Loess. Sedimentary rocks are formed from the accumulation and consolidation of sediment over time. Loess is a type of sedimentary rock that is made up of fine particles of wind-blown dust and silt. It is typically of a yellowish-brown color and has a loosely compacted structure. This type of rock is often found in areas with a history of strong winds, such as desert regions or river valleys. In contrast, options 2, 3, and 4 (Basalt, Granite, and Gabbro) are examples of igneous rocks, which are formed from the cooling and solidification of molten lava or magma. Therefore, they do not fit the criteria for sedimentary rocks.