Question

Choose appropriate question using given words:

Ask about silver. (what/use for?) ________________

• A. What silver is used for?
• B. What is silver used for?
  
• C. What has silver been used for?
• D. What silver has been used for?

Answer 1

Answer: (B)

The correct option is C What is silver used for?
Passive voice is used when actions are more important than the doer.

Here same is indicated;

The syntax for simple present tense - passive voice - in interrogation is:

w/h word + helping verb (is/am/are) + object + verb in the third form?

Therefore the correct option is:

What is silver used for?