Multiple choice general knowledge foreign languages

Which of the following is grammatically incorrect?

  1. This is where I'm working right now.

  2. This is what I'm at right now.

  3. This is where I am right now.

  4. That is where I'm working right now.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Where is a relative adverb used for locations, but what cannot function as a locative adverb. The phrase what I'm at attempts to use what as a locative, which is grammatically invalid. The correct form would be where I'm at or where I am.