Step 1: Understanding the Concept:
The question asks to complete the definition of "sweetened condensed milk". The name itself provides a strong clue. This product is preserved not by heat sterilization, but by high sugar concentration.
Step 2: Detailed Explanation:
Sweetened condensed milk is manufactured by evaporating a portion of the water from milk and then adding a significant amount of sugar.
(A) Addition of cane sugar: This is the defining ingredient. The high concentration of sugar (sucrose or cane sugar) increases the osmotic pressure to a level that inhibits the growth of most microorganisms, thus preserving the product.
(B) Addition of salt: Salt is not a primary ingredient in sweetened condensed milk.
(C) Addition of milk powder: Milk powder might be used to standardize the milk solids, but it is not the key additive that defines the product as "sweetened". The primary process is water removal, not addition of solids.
(D) Addition of citric acid: Citric acid is an acidulant and would cause the milk proteins to coagulate. It is not used in this product.
Step 3: Final Answer:
The defining characteristic of sweetened condensed milk, besides water removal, is the addition of cane sugar for preservation and sweetness.