Salt is gradually reduced in processed foods and in restaurant menus over the course of a decade. which of the following public health strategies best describes this approach?

The correct answer is- improving the average

Explanation:

WHO recommended the amount of salt that should be taken per day and that amount is less than 5 gm for adults. Unfortunately, people around the world are moving towards processed food which normally contains a high amount of saturated fat and salt.

Reduction in salt intake shows the improvement in the health of a country population so over the course of decade the salt in processed food and restaurant menus gradually decreased which shows average improving health strategy which is focused on entire population health.  

i agree d is most definitely correct!