Answer: 0.25
Explanation: A ratio represents a number representing a comparison between two named things (milk and sauce in this case.) it is the relative magnitudes of the two quantities (usually expressed as a quotient). And since the recipe uses 4 ounces of milk to 16 ounces if salt, then the ratio of milk to salt could be gotten by dividing 4 ounces by 16 ounces.
4/16 = 2/8 = ¼
This is the fractional ratio. ¼ to decimal give 0.25 as the correct answer.