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").
Q: Fact1: electrocution causes harm to an organism, Fact2: Hair dryers without built-in shock protection devices in the plug can cause electrocution., Question: What can be done to make hair dryers safer? (A) remove plastic covering (B) immerse in water (C) heating liquids (D) Add shock protection (E) converting electricity to heat (F) Electric generators (G) a hydraulic system (H) increase current
A:
D