Which statement is used to access an existing Database?

Answer: Option C

This question is asking about how you "switch" to a specific database in MySQL. You need to tell MySQL which database you want to work with.

Let's break down the options:

Option A: Use
This is incorrect. "Use" is a keyword in MySQL, but it needs a database name after it.

Option B: use database.name
This is also incorrect. You don't use a dot (.) to separate the "use" keyword and the database name.

Option C: USE databasename;
This is the correct answer! "USE" is the command, followed by the name of your database, and ending with a semicolon (;).

Option D: None of the mentioned
This is incorrect because Option C is the correct way to access an existing database.

In summary: To access an existing database in MySQL, use the command: USE databasename; (Replace "databasename" with the actual name of your database).