Having an insufficient daily diet is called
a. agriculture
b. supply and demand
c. production
d. malnourishment

The answer is letter D.  

Malnourishment also known as malnutrition is a result of the lack or excess amounts of proper nutrients in the body. When a person is malnourish health problems are always attached to them. Calories, protein, carbohydrates, vitamins, and minerals are the major nutrients that a balanced diet should have. Malnutrition is mostly common in third world countries where adults and kids alike are affected due to poor living conditions. If left untreated for a long time, this condition will result to severe starvation or worst death.  

A. vitamin c is your answer