**Core Concept**
In healthcare settings, IV fluids are often prepared by diluting a concentrated solution with a solvent, in this case, normal saline, to achieve the desired concentration. This process requires understanding the concept of dilution and the importance of accurate calculations to prevent errors.

**Why the Correct Answer is Right**
To prepare normal saline from 10% Dextrose (per 100 ml), the staff nurse should first calculate the amount of Dextrose required for a specific volume of normal saline. The formula for dilution is: M1V1 = M2V2, where M1 and V1 are the concentration and volume of the initial solution, and M2 and V2 are the desired concentration and volume of the final solution. In this case, the initial solution is 10% Dextrose (per 100 ml), and the desired solution is normal saline. To prepare 1 L of normal saline, the nurse would need to add 1000 ml of normal saline to 10 ml of 10% Dextrose.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not provide a clear calculation or method for preparing normal saline from 10% Dextrose.
* **Option B:** This option is incorrect because it suggests adding a specific volume of normal saline to 10% Dextrose without providing a clear calculation or reasoning.
* **Option C:** This option is incorrect because it suggests using a different concentration of Dextrose (20%) without providing a clear explanation or justification.

**Clinical Pearl / High-Yield Fact**
When preparing IV fluids, it's essential to double-check calculations and consider the concentration of the initial solution to prevent errors. A simple mnemonic to remember the formula for dilution is: "M1V1 = M2V2" or "Concentration x Volume = Desired Concentration x Desired Volume".

**Correct Answer: D. 10 ml of 10% Dextrose in 1000 ml of normal saline.**