**Core Concept**
Akalinisation of urine is a medical treatment strategy to enhance the excretion of certain drugs or toxins from the body. It involves increasing the pH of the urine to a more alkaline state, typically above 7.5, to promote the elimination of weak acids.

**Why the Correct Answer is Right**
The mechanism behind akalinisation of urine is based on the principle of ion trapping. Weak acids, such as aspirin, phenobarbital, and salicylates, are more ionised and less soluble in alkaline urine. By increasing the pH of the urine, these weak acids become more ionised and are trapped in the urine, making it easier for the kidneys to excrete them. This process is mediated by the renal tubular cells, which reabsorb sodium and hydrogen ions in exchange for potassium ions, thereby increasing the pH of the urine.

**Why Each Wrong Option is Incorrect**
**Option A:** This is incorrect because alkalinisation of urine is not typically used for the treatment of poisoning with weak bases, such as amphetamines or cocaine.
**Option B:** This is incorrect because alkalinisation of urine is not typically used for the treatment of poisoning with strong acids, such as hydrochloric acid or sulfuric acid.
**Option C:** This is incorrect because alkalinisation of urine is not typically used for the treatment of poisoning with substances that are primarily excreted unchanged by the kidneys, such as ethanol.

**Clinical Pearl / High-Yield Fact**
A classic exam trap is the misconception that alkalinisation of urine is used to treat poisoning with all types of weak acids. However, it is essential to remember that alkalinisation of urine is only effective for weak acids that are not highly protein-bound or highly lipid-soluble.

**Correct Answer: D. Salicylates**