Step 1: Understanding the Concept:
Oceanography and bathymetry of ocean trenches: the Java Trench (Sunda Trench) reaches the maximum depth in the Indian Ocean ($7,450 ext{ m} / 24,440 ext{ ft}$).
Step 2: Detailed Explanation:
Deepest oceanic trenches across the major oceans:
1. Java Trench (Sunda Trench) (A): Located in the northeastern Indian Ocean along the southern Indonesian arc; reaches a maximum surveyed depth of 7,450 meters (24,440 feet), making it the deepest trench in the Indian Ocean.
2. Mariana Trench: Deepest trench in the world and Pacific Ocean ($10,994\text{ m}$ Challenger Deep).
3. Puerto Rico Trench: Deepest trench in the Atlantic Ocean ($8,376\text{ m}$ Milwaukee Deep).
4. Vema Trench (Deep): Deep fracture trench in the central Indian Ocean ($5,400\text{ m}$).
Step 3: Final Answer:
Therefore, the deepest trench in the Indian ocean is Java trench, matching option (A).