**Core Concept**
The World Health Organization (WHO) has established guidelines for acceptable levels of various electrolytes in the human body. In this context, the question pertains to the chloride level, which is a crucial electrolyte that plays a vital role in maintaining proper fluid balance, nerve function, and muscle contraction.

**Why the Correct Answer is Right**
The correct chloride level varies depending on age, sex, and other factors. However, the WHO recommends that the chloride level should be between 96 and 106 mmol/L for adults. This range allows for optimal physiological functions and prevents potential complications associated with hypo- or hyperchloridemia. The chloride level is often measured alongside other electrolytes, such as sodium and potassium, to assess overall electrolyte balance.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we cannot evaluate its correctness.
**Option B:** This option is also not provided, so we cannot evaluate its correctness.
**Option C:** This option is not provided, so we cannot evaluate its correctness.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the WHO guidelines for electrolyte levels serve as a general reference for healthcare professionals. However, individual patient needs may vary, and clinical judgment should be exercised when interpreting laboratory results.

**Correct Answer: D. 96-106 mmol/L**