Which of the following command is used to underline a selected text ?

The correct answer is (a) Ctrl + u.

Ctrl + u is the keyboard shortcut for underlining a selected text. It is used in many different applications, including Microsoft Word, Google Docs, and Adobe Acrobat. To underline a text using Ctrl + u, simply select the text you want to underline and then press the Ctrl and u keys at the same time.

Ctrl + b is the keyboard shortcut for bolding a selected text. Ctrl + c is the keyboard shortcut for copying a selected text. Ctrl + v is the keyboard shortcut for pasting a copied text.

I hope this helps!