Which of the following represents a simple selection example?

• A. Calculate the sum of rainfall
• B. Select all rows where rainfall > 50 for further analysis
• C. Group by location
• D. Remove rows with missing dates

Answer: (B)

Filtering data by a condition to keep only the rows that meet that condition is what “simple selection” is about. The best example is selecting all rows where rainfall > 50 for further analysis. This operation applies a test to each row and retains only the ones that pass, leaving a subset of the data for deeper work.

The other tasks involve different types of data manipulation: calculating the sum of rainfall is an aggregation that produces a total rather than a subset of rows; grouping by location reorganizes data to summarize by categories; removing rows with missing dates is a cleaning step aimed at excluding incomplete records rather than filtering by a value criterion.