The correct option is 1. A common use case for the $GLOBALS superglobal in PHP is accessing or manipulating global variables within functions or classes. When you need to access a global variable from within a function or class, you can use the $GLOBALS superglobal to retrieve its value or modify it directly. This allows you to work with global variables without having to use the global keyword within each function or class method. However, it is generally recommended to minimize the use of global variables and consider alternative approaches, such as passing variables as parameters or using object-oriented design principles, for better code organization and maintainability. Learn more: https://www.php.net/manual/en/reserved.variables.globals.php

If you try to use a foreach loop on a non-array variable in PHP, it will result in a "Fatal error." This error occurs because the foreach loop expects an array as its argument to iterate over. If you attempt to use a non-array variable, PHP will throw a fatal error and halt the script execution. It is important to ensure that the variable passed to the foreach loop is an array to avoid encountering this error. Learn more: https://www.php.net/manual/en/control-structures.foreach.php

Functions in PHP are commonly used for input validation, database management, file manipulation, and many other tasks. They allow for code reuse and modular organization, making the code more maintainable and readable. Functions can be created to perform specific tasks and then called whenever needed within the PHP script. Learn more: https://www.php.net/manual/en/functions.user-defined.php

To establish an FTP connection in PHP, you can use the ftp_connect() function. This function takes the FTP server hostname as the parameter and returns a connection resource. For example, $connection = ftp_connect($ftpServer); establishes an FTP connection to the specified server and stores the connection resource in the $connection variable. This resource is then used for subsequent FTP operations such as uploading files or retrieving directory listings. The ftp_connect() function is specifically designed for establishing FTP connections in PHP.

The str_replace() function in PHP is used to replace all occurrences of a substring in a string with a specified replacement. It takes the substring to be replaced, the replacement string, and the input string as parameters and returns the modified string. This function is useful for string manipulation and replacing specific content. Learn more: http://php.net/manual/en/function.str-replace.php

OSPF (Open Shortest Path First) determines the best route based on the cost, which is calculated using link speed. Lower cost indicates a better route.

Virtualization technology enables different operating systems to run on a single physical hardware resource in cloud environments.

Standard ACLs are typically used to permit or deny traffic from specific IP addresses.

HSRP uses priority values to determine the active and standby routers in a network. The router with the highest priority becomes the active router.

SDN introduces centralized control, allowing for more efficient device monitoring and management by abstracting control from the physical devices.