You are migrating a large database to Azure SQL Database. Which tool helps estimate cost and performance impact before migration?

Correct answer: Database Migration Assistant (DMA)

Option A is correct because the Database Migration Assistant (DMA) is a Microsoft tool specifically designed to assess on-premises SQL Server and Azure SQL Database readiness, identify compatibility issues, and estimate performance impact before migration. Option B is incorrect because Azure Migrate is a broader service for discovering and migrating servers, virtual machines, and applications, but DMA provides deeper SQL Server-specific assessment and compatibility analysis. Option C is incorrect because SQL Server Management Studio is a database administration and development tool, not a migration assessment tool. Option D is incorrect because Azure Data Studio is a cross-platform database editor and query tool, not a pre-migration cost and performance assessment utility.