Given the task definition, example input & output, solve the new input case.
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").
Example: Fact1: a plant requires sunlight to grow, Fact2: Plants to avoid are fast-growing vines that can take over an area in no time., Question: What requires sunlight in order to take over an area? (A) spores (B) fish (C) plants (D) humans (E) pods (F) Oak (G) opossums (H) coral
Output: C
This is a good example. Based on the facts plants require sunlight in order to take over an area.

New input case for you: Fact1: carbon dioxide concentrations in the air have increased over the last decade dramatically, Fact2: Carbon dioxide is the primary greenhouse gas., Question: What have increased over the last decade dramatically (A) gasoline concentrations (B) Warm air moving into cold air (C) Greenhouse gases (D) treehouse gas concentrations (E) movements in the earth's crust (F) concentrated orange juices (G) genetic diversity (H) greenhouse gas concentrations
Output:
H