In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").

[EX Q]: Fact1: creating paper requires cutting down trees, Fact2: Deforestation takes place when trees are cut down in the rainforest., Question: What can cause deforestation? (A) Planting flowers (B) Creating paper (C) Greenhouse gases (D) Filtering water (E) Greenhouse gasses (F) Cutting grass (G) Pesticides (H) Pollution
[EX A]: B

[EX Q]: Fact1: erosion causes a river to become deeper and wider, Fact2: Weathering and erosion continue to shape it today., Question: Weathering causes what to become deeper and wider? (A) a landslide (B) Sediment (C) a mountain (D) a volcano (E) soils (F) rock (G) flooding (H) a river
[EX A]: H

[EX Q]: Fact1: Ancestors of hagfish are thought to have been the earliest vertebrates., Fact2: Hagfishes are a type of jawless fish which are the only parasitic vertebrates., Question: Ancestors of a jawless fish which is parasitic are thought to have been the earliest what (A) moving over land (B) changes in size (C) aquatic (D) reptile (E) several (F) chondrocytes (G) vertebrates (H) eukaryotic cells
[EX A]:
G