Consider the following relational schema for an online programming platform:

Write appropriate SQL queries for the questions below. For each question write a single query:

A. Retrieve the username and ranks of all users from highest to lowest rank [3]

B. Retrieve the username, id and rank of all users who have the lowest rank [3]

C. Retrieve the total number of submissions for each question with "medium" difficulty level. The query should show question id and number of submissions [4]

Consider the following relational schema for an online programming platform:

Write appropriate SQL queries for the questions below. For each question write a single query:

A. Retrieve the username and ranks of all users from highest to lowest rank [3]

B. Retrieve the username, id and rank of all users who have the lowest rank [3]

C. Retrieve the total number of submissions for each question with "medium" difficulty level. The query should show question id and number of submissions [4]