How many of the following does not return a value? mysql_close(), mysql_init, mysql_real_connect

Answer: Option B

This question asks about functions in MySQL, specifically how many of them don't return a value. This means they don't give you any output or result after you run them.
Let's break down each function:
mysql_close(): This function closes a connection to a MySQL server. It doesn't need to return anything because its job is simply to end the connection.
mysql_init: This function initializes a MySQL connection handle. It prepares the connection handle for later use. It doesn't return a value because its primary purpose is to set up things, not provide an output.
mysql_real_connect: This function establishes a real connection to a MySQL server. It doesn't need to return a value because it focuses on the connection process.
Therefore, all three functions don't return a value.
The answer is Option D: 3