What is the use of the compound shown in the image?

Some drugs bind to a site other than the active site of an enzyme. This site is known as:

Which of the following is not correctly matched?

The use of chemicals for therapeutic effect in the treatment of diseases is called ...... .

The statement/s which are true about antagonists from the following is/are :-
$A.$ They bind to the receptor site.
$B.$ Get transferred inside the cell for their action.
$C.$ Inhibit the natural communication of the body.
$D.$ Mimic the natural messenger.
Choose the correct answer from the options given below :-

Which of the following is a local anaesthetic?