You need to load a script without blocking the HTML parser during the loading phase. How would you use the "async" and "defer" attributes to achieve this, and what are the key differences between them?

Use "async" and "defer" interchangeably as they have identical functionalities.
Use "async" to load the script after the HTML is parsed and "defer" to execute the script immediately.
Use "async" to load the script in parallel and execute it as soon as it finishes downloading; use "defer" to load the script in parallel but defer its execution until after the HTML is parsed.
Use "async" to pause the HTML parser and "defer" to load the script in parallel.

Both "async" and "defer" are attributes used with