To insert slide numbers A. Insert a text box and select Insert >> Page Number B. Insert a textbox and select Insert >> Number >> PageNumber C. Choose Insert >> Slide Number D. Insert a new text box and select Insert >> slide Number

The correct answer is: C. Choose Insert >> Slide Number.

To insert slide numbers in PowerPoint, follow these steps:

1. On the Insert tab, in the Text group, click the Header & Footer button.
2. In the Header & Footer dialog box, on the Slide tab, under Header and Footer, select the Slide number check box.
3. To change the position of the slide number, click the Align button and select an alignment option.
4. To format the slide number, click the Format button and select the options you want.
5. Click Apply to All.

Option A is incorrect because it does not specify that the text box should be inserted on the slide. Option B is incorrect because it does not specify that the number should be inserted in the header or footer. Option D is incorrect because it does not specify that the slide number should be inserted from the Insert menu.