Which command should you select to delete a comment?

Delete command is used to delete the comment.

Explanation:

When a user using any type of text document and he needs to delete some 'comment' or 'line' or 'text' from the document then he needs to select the text and press 'delete' button from the keyboard and the text or comment or line will be deleted from the document.When a user wants to delete all the text from any document then he needs to firstly select all the text by pressing 'control+A' (firstly press the control key from the keyboard and then press A key without relieving the control key from the keyboard) and then delete the selected text by pressing the 'delete' key from the keyboard.

Iwould go with either b or c, not sure which one.