In graphical user interfaces, which of the following menu types is also commonly called a drop down menu, where a list of options appears below the menu title when it is clicked?

Introduction / Context:
Graphical user interfaces use menus to organise commands in a structured way. One common type is the menu that appears when you click a title in the menu bar at the top of a window. The menu list appears to drop down from the title and then disappears when a choice is made. This type of menu has specific names, and understanding them is useful in basic computer literacy and interface design questions.

Given Data / Assumptions:

• The question asks which menu type is also called a drop down menu.
• The options include fly-out, cascading, pop-up, and pull-down.
• We assume standard desktop interfaces where menus are shown in a bar at the top of application windows.
• The drop down effect refers to the menu opening downward from the menu title.

Concept / Approach:
A pull down menu (also written pull-down menu) is a menu that drops down vertically when the user clicks on a menu title in a menu bar, such as File or Edit. A cascading menu is a secondary menu that appears to the side of another menu item, creating a cascade. A pop up menu appears when the user right-clicks on a screen area or object, popping up at the pointer location. Fly-out is sometimes used to describe side appearing submenus, similar to cascading menus. The term most commonly associated with a drop down menu from the menu bar is pull down menu.

Step-by-Step Solution:
Step 1: Visualise a menu bar at the top of a program window (File, Edit, View, etc.). Step 2: When you click File, a list of commands drops down from the menu bar. This is the drop down or pull down menu. Step 3: Recognise that pop up menus appear at the cursor position, not as a drop from the menu bar. Step 4: Recognise that cascading or fly-out menus appear to the side of an existing menu. Step 5: Match “drop down menu” with the term “pull-down menu”.

Verification / Alternative check:
User interface guidelines and textbooks often use the terms drop down menu and pull down menu interchangeably when describing the menus under headings in the menu bar. They distinguish these from pop up menus, which appear on right-click, and cascading menus, which extend sideways from an existing menu item. Example screenshots in such materials label the menu that drops from the top bar as a pull down menu. This confirms that the correct phrase related to drop down menus is pull down menu.

Why Other Options Are Wrong:
Option A (fly-out): Usually used to describe side appearing submenus that fly out from an existing menu item, not the top level drop down from a menu bar. Option B (cascading): Refers to submenus that cascade to the side from a parent menu item. Option C (pop-up): Refers to menus that appear at the pointer location, often on right-click, not dropping down from the menu bar.

Common Pitfalls:
Learners sometimes confuse pop up and drop down menus because both appear over the main window. Another confusion arises from seeing cascade arrows inside a pull down menu and assuming the entire menu is called a cascading menu. To avoid mistakes, remember that menus dropping from the top bar are called pull down (drop down) menus, while menus appearing at the pointer are pop ups, and side extending submenus are cascading or fly-out menus.

Final Answer:
The menu type that is also called a drop down menu is a pull-down menu.