The correct answer is D. Glittering things may be deceptive.
The phrase “All that glitters is not gold” means that not everything that looks good is actually good. It is often used to warn people not to be fooled by appearances. For example, someone might say this to someone who is about to invest in a business that seems too good to be true.
Option A is incorrect because it is possible for non-metals to glitter. For example, some types of plastic can glitter.
Option B is incorrect because it is possible for things that are not gold to glitter. For example, some types of rocks can glitter.
Option C is incorrect because it is possible for some metals to glitter. For example, gold and silver both glitter.
Option E is incorrect because it is not related to the meaning of the phrase “All that glitters is not gold.”