In MS-PowerPoint (MS-PPT), the font dialog box allows several text effects, including underline, shadow, and emboss. However, Strikethrough is not available as a direct font effect in MS-PPT's font dialog box, though it can be applied via other formatting options like the text formatting toolbar or shortcuts.
Step 1: Font Effects in MS-PPT
The Underline, Shadow, and Emboss effects are readily available in the font dialogue box in MS-PPT. These are basic text effects that you can apply directly to the selected text.
Step 2: Conclusion
Thus, Strikethrough is the correct answer because it is not directly available in the font dialogue box.
Final Answer: Strikethrough.