Three-tier architecture benefits: Which statement best captures a key benefit of adopting a three-tier (presentation, application, data) architecture in enterprise systems?

Introduction / Context:
Three-tier architecture separates responsibilities into presentation (UI), application (business logic), and data (DB). This separation improves maintainability, scalability, and the ability to evolve systems without disrupting all layers.

Given Data / Assumptions:

• Business logic can live on an application server.
• Multiple client types (web, mobile) may consume the same services.
• The database focuses on persistence and set-based processing.

Concept / Approach:

Modularity enables adding new business modules (APIs/services) without altering clients extensively. Centralizing logic on an app tier lightens the client and can reduce ad-hoc burdens on the DB, effectively making both “thinner.” While compiled SQL performance mainly depends on the database, three-tier designs facilitate pooling, caching, and optimized call patterns that indirectly improve performance of repeated statements.

Step-by-Step Solution:

Verification / Alternative check:

Measure throughput after introducing an app tier with pooled connections and cached results; observe reduced DB contention.

Why Other Options Are Wrong:

Options A and C are true on their own; B is plausible via better call patterns and reuse—hence “All of the above.”

Common Pitfalls:

Assuming three tiers automatically improve performance without proper design; duplicating logic across tiers.

Final Answer:

All of the above.