In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

An early example of harnessing wind power would be (A) unicorns (B) santas flying reindeer (C) trumps windy speeches (D) cloth on masts
D

Magnetic media, such as TVs, computer monitors, credit cards and pacemakers can be damaged when exposed to (A) neodymium (B) a paper clip (C) copper penny (D) metal nails
A

What might have more closely packed matter (A) air (B) wood (C) gold (D) water

C