“while big guns like hedge funds are biting their nails.” What type of figurative language would “biting their nails” be?

One person's trash is another person's treasure. instead of discarding unwanted appliances, tools, or clothes, try selling or donating them. karen wants to explain that discarding means "throwing away." which of the following passages has karen written correctly? "one person's trash is another person's treasure. instead of discarding . . throwing away . . unwanted appliances, tools, or clothes, try selling or donating them." "one person's trash is another person's treasure. instead of discarding--throwing away--unwanted appliances, tools, or clothes, try selling or donating them." "one person's trash is another person's treasure. instead of discarding [throwing away] unwanted appliances, tools, or clothes, try selling or donating them." "one person's trash is another person's treasure. instead of discarding (throwing away) unwanted appliances, tools, or clothes, try selling or donating them."