Answer:
B. Tool bar
Step-by-step explanation:
A menu bar contains window or application specific menus for specific functions such as opening and saving a file.
A tool bar contains functions that are commonly performed in a program such as editing fonts, making text bold and so on.
A scroll bar which could be horizontal or vertical, allows users to move the application window view up, down, left or right for easy viewing.
A status bar contains the information of the application's current state and other information such as time, date, size of window's viewing port and so on.
Rulers are just used to measure the layout of the page and to give a "look and feel" view of the dimensions of the page.
Therefore, a tool bar is the correct option.
Hope this helps!