Much of the clothing people give away ends up in a landfill or an incinerator.
This is the best choice for a presentation about clothing and waste. The sentence clearly tells how clothing and waste are related. It tells the audience that clothing that is given away becomes waste. The first option about buying new clothing instead of repurposing old clothing does not explain that this creates waste. The second option about purchasing clothing secondhand to conserve resources also does not indicate waste. The option about upcycling clothing gives a suggestion of how to recycle clothing, but still doesn't directly show that upcycling is beneficial because it reduces waste. The last option is the only one that specifically indicates that discarded clothing creates waste.
