The correct answer is option 'A': Common tasks toolbar.

The Common tasks toolbar is a toolbar that provides different options in various master views in Microsoft PowerPoint. Let's discuss each of the toolbars mentioned in the options to understand why the Common tasks toolbar is the correct answer.

a) Common tasks toolbar:
The Common tasks toolbar is a customizable toolbar that provides quick access to commonly used commands and options. It is designed to change its options based on the active view or task. In PowerPoint, the Common tasks toolbar provides different options in various master views. For example, when you are in the Slide Master view, the Common tasks toolbar will display options related to editing the slide master, such as changing the background, adding placeholders, and modifying layouts. When you switch to the Handout Master view or Notes Master view, the Common tasks toolbar will adjust and display options specific to those views. This toolbar makes it easy to access relevant commands and options based on the active view.

b) Drawing toolbar:
The Drawing toolbar in PowerPoint provides tools and options for creating and formatting shapes, lines, and other drawing objects. It is not directly related to different options in various master views. The Drawing toolbar is primarily used for creating and editing graphics within a slide.

c) Formatting toolbar:
The Formatting toolbar in PowerPoint provides options for formatting text and objects on a slide. It includes options for changing font styles, alignment, bullet points, and more. While the Formatting toolbar is useful for formatting content within a slide, it does not provide different options in various master views.

d) Standard toolbar:
The Standard toolbar in PowerPoint includes commonly used commands such as saving, printing, undoing or redoing actions, and formatting text. It does not provide different options specific to master views.

In conclusion, the Common tasks toolbar is the correct answer as it is designed to provide different options in various master views in PowerPoint, whereas the other toolbars mentioned in the options do not have this functionality.

Answer:
The correct answer is A: Common tasks toolbar.
The Common tasks toolbar is a toolbar that provides different options in various master views in a document. It is designed to assist users in performing common tasks easily and efficiently.
Here are the reasons why the other options are not correct:
B: Drawing toolbar:
- The Drawing toolbar is mainly used for creating and manipulating drawings, shapes, and images. It is not specifically designed to provide options in various master views.
C: Formatting toolbar:
- The Formatting toolbar is used for formatting text, paragraphs, and objects within a document. It does not specifically provide options in various master views.
D: Standard toolbar:
- The Standard toolbar is a general-purpose toolbar that provides quick access to commonly used commands and functions. It does not provide options specifically for various master views.
In conclusion, the Common tasks toolbar is the correct answer as it is specifically designed to provide different options in various master views.