**Core Concept**
Barrett's oesophagus is a pre-malignant condition characterized by the replacement of the normal stratified squamous epithelium of the oesophagus with simple columnar epithelium, often containing goblet cells. This transformation is a result of chronic gastroesophageal reflux disease (GERD), leading to an increased risk of developing oesophageal adenocarcinoma.

**Why the Correct Answer is Right**
The pathophysiology of Barrett's oesophagus involves the chronic exposure of the oesophageal mucosa to acidic gastric contents, leading to chronic inflammation and subsequent metaplastic changes. The replacement of the normal squamous epithelium with columnar epithelium, often containing goblet cells, is a hallmark of this condition. This transformation is thought to be mediated by the activation of transcription factors, such as SOX2 and KLF4, which promote the expression of genes involved in the development of columnar epithelium.

**Why Each Wrong Option is Incorrect**
**Option A:**
This option is likely incorrect as it does not accurately describe a feature of Barrett's oesophagus.

**Option B:**
This option may be tempting, but it is not a specific feature of Barrett's oesophagus. While dysplasia is a characteristic of this condition, it is not a defining feature.

**Option C:**
This option is incorrect as it is a symptom of GERD, not a feature of Barrett's oesophagus.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize that Barrett's oesophagus is a pre-malignant condition, and patients with this condition should be closely monitored for the development of dysplasia and oesophageal adenocarcinoma. A key step in the diagnosis of Barrett's oesophagus is the visualization of goblet cells on biopsy, which is a characteristic feature of this condition.

**Correct Answer: C. Dysphagia.**