ANS:D - 0.94

The percentage of argon (by volume) in dry atmospheric air is about 0.94%. Dry atmospheric air is composed of approximately 78.08% nitrogen, 20.95% oxygen, and small amounts of other gases, including argon. Argon is an inert gas and makes up about 0.93-0.94% of dry air by volume. Therefore, the correct percentage of argon (by volume) in dry atmospheric air is approximately 0.94%.