What can be inferred from Para. 3?

参考解析：

推理判断题。根据第三段第二句“But ordering a pizza, a spicy curry or a box of noodles can come at a price both financially and to our health”可知，点外卖使我们在经济上和健康上都要付出代价，即点外卖会贵一些，并且对健康有害，A项错误，C项错误；根据第三段第一句“It’s no wonder we … enjoy something that someone else has prepared”可知，点外卖不足为奇，B项错误；根据第三段最后两句“most people ate fast food on average two days per week. But, in the 16 to 20-year-old category, one in six ate fast food at least twice a day.”可知，大多数人平均每周吃两天快餐，而16到20岁的青少年中，六分之一的人每天至少吃两次快餐，所以年轻人吃快餐更频繁，D项正确。故选D。