When client books ad in newspaper, he has to pay 18% GST to newspaper owner who deposits it to Government. but when such newspaper is sold to public, they are not required to pay newspaper price + GST. so, #4 is exempted from GST. Processed / Canned food (#3) is subject to GST. So, by elimination, we get correct answer c. Some experts were divided that if eggs are cooked in a 5-star hotel, it'll be subjected to GST however UPSC's Official Answer key has kept c is the correct option.