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").

Fact1: Biodiversity generally increases from the poles to the equator., Fact2: Biodiversity contributes to ecosystem complexity., Question: Where is ecosystem complexitiy generally least? (A) humans disturb it (B) frontal zones (C) in lakes (D) at the ocean (E) our planet (F) at the poles (G) mouth of rivers (H) at the equator
F