Final answer:
An inner join is a type of join in databases where the result set includes rows with matching values in common columns from both tables involved in the join. The correct answer is A) Inner. It is commonly used in SQL and relational database querying.
Step-by-step explanation:
A join that is based upon data having equivalent data in common columns is known as a(n) inner join. The correct answer to this question is A) Inner. An inner join combines rows from two or more tables based on a related column between them and returns rows where there is a match in both tables.
For example, consider two tables, Table A and Table B. If we perform an inner join on these tables with a common column, say ID, the result will include only those records where the ID exists in both Table A and Table B. Rows that do not have a matching ID in either table will be excluded from the result set.
An inner join is commonly used in SQL databases and is a fundamental concept in relational database design and querying.