If emp_id contain the following set 9, 7, 6, 4, 3, 1, 2, what will be the output on execution of the following MySQL command? SELECT emp_id FROM person ORDER BY emp_id ASC;

Answer: Option B

This question asks about how data is arranged in a database using MySQL. Let's break it down:
What is `emp_id`?
`emp_id` is a column in a table named `person`. It stores the unique identification numbers of employees.
What does `SELECT emp_id` do?
This part of the command tells MySQL to get the values from the `emp_id` column.
What does `FROM person` do?
This part tells MySQL to get the data from the table named `person`.
What does `ORDER BY emp_id ASC` do?
This is the key part! `ORDER BY` tells MySQL to arrange the results in a specific order. `ASC` stands for "Ascending," which means it will arrange the values from the smallest to the largest.
What is the output?
Given the `emp_id` values {9, 7, 6, 4, 3, 1, 2}, the `ORDER BY emp_id ASC` will arrange them in ascending order.
Therefore, the correct answer is Option B: {1, 2, 3, 4, 6, 7, 9}.