Step 1: Understanding the Question:
Economic activities are classified as primary (direct extraction from nature), secondary (processing/transforming raw material), tertiary (services), and quaternary (knowledge-based).
Step 2: Classify each option:
Agriculture and Mining directly extract from nature → primary activities. Trade is a service that moves/exchanges goods → tertiary activity. Manufacturing processes raw material into a new, finished product → secondary activity.
Step 3: Final Answer:
\[ \boxed{\text{Manufacturing}} \]