What is the more recent effort by food companies to make foods and drinks both healthy and tasty? ( )

参考解析：

题干问食品公司最近在使食品和饮料既健康又美味方面做了哪些努力？定位第三段，Some companies have been investing money in a more ambitious undertaking: learning how to adjust the fundamental make-up of the food they sell. For example, having salt on the outside, but none on the inside, reduces the salt content without changing the taste.最近一些公司开始投资一项更加雄心勃勃的事业：学习如何调整他们销售的食品的基本成分。例如，外面有盐，而里面没有，可以在不改变味道的情况下减少盐的含量。选项A：用替代材料代替糖或盐；选项B：限制他们产品中糖或盐的含量；选项C：投资研究以找到适应消费者需求的方法；选项D：调整产品的组成。故本题正确答案选D。