**Core Concept**
Linitis plastica is a form of chronic gastric atrophy characterized by a thickening of the stomach wall due to diffuse infiltration of gastric mucosa by cancer cells, often leading to a rigid and leather-like appearance of the stomach.

**Why the Correct Answer is Right**
The correct answer is gastritis caused by malignant cells. Linitis plastica is associated with diffuse gastric adenocarcinoma, where the cancer cells infiltrate the gastric mucosa, leading to fibrosis and thickening of the stomach wall. This results in a loss of gastric folds and a rigid, leather-like appearance of the stomach, which is a characteristic feature of linitis plastica.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not correct as linitis plastica is not typically associated with acute gastritis, which is characterized by inflammation of the gastric mucosa.

**Option B:** This option is not correct as linitis plastica is not typically associated with peptic ulcer disease, which is characterized by erosion of the gastric or duodenal mucosa.

**Option C:** This option is not correct as linitis plastica is not typically associated with gastric polyps, which are benign growths on the gastric mucosa.

**Clinical Pearl / High-Yield Fact**
Linitis plastica is a type of gastric cancer that can be difficult to diagnose, as it often presents with non-specific symptoms such as weight loss and abdominal pain.

**Correct Answer:** D.