**Core Concept**
Salivary calculus, also known as sialolithiasis, refers to the formation of stones within the salivary glands. The underlying principle being tested is the anatomical and physiological characteristics of the salivary glands that predispose certain glands to the development of calculi.

**Why the Correct Answer is Right**
The submandibular gland is more prone to sialolithiasis due to its unique anatomy. The submandibular gland's duct, known as the Wharton's duct, is longer and more tortuous compared to the ducts of other salivary glands. This increased ductal length and complexity contribute to the higher incidence of stone formation in the submandibular gland. Additionally, the submandibular gland's higher concentration of calcium and phosphate ions in its secretions may also play a role in the development of calculi.

**Why Each Wrong Option is Incorrect**
**Option B:** The sublingual gland is less likely to develop calculi due to its shorter and more direct ductal system, making it less prone to stone formation.
**Option C:** The parotid gland is the largest salivary gland, but its ductal system is shorter and more straight, reducing the risk of calculus formation.
**Option D:** Minor salivary glands are scattered throughout the oral cavity and are not prone to calculus formation due to their small size and short ductal systems.

**Clinical Pearl / High-Yield Fact**
It's essential to note that sialolithiasis often presents with pain and swelling in the affected gland, and a thorough history and physical examination are crucial in diagnosing this condition.

**✓ Correct Answer: A. Submandibular gland**