Dry ice, ammonium chloride, naphthalene balls and camphor, all these compounds are an example of:

Correct option is A

The correct answer is (a) Sublimable substances.
 Dry ice (solid CO₂), ammonium chloride, naphthalene balls, and camphor are all substances that undergo sublimation.
 Sublimation is the process where a substance transitions directly from a solid to a gas without passing through the liquid state.
 These substances have a characteristic property of subliming at certain temperatures.
 Dry ice sublimates at -78.5°C, making it useful for cooling and refrigeration.
 Ammonium chloride, naphthalene balls, and camphor are often used for their sublimation properties in various applications such as moth repellents and air fresheners.