The mancalled me was Ahmed?
-which
-where
-who
-whom

The tricky part is knowing the difference between whom and who. We obviously know it’s not which or where because it doesn’t make sense or sound right within the sentence.

Here is a little trick to know the difference between whom and who:
If you could use ‘he’ or ‘she’ in the blank then use who. If you could use ‘him’ or ‘her’ in the black use whom.

So let’s look at it, which one of these sentences sounds right?
1- The man he called me is ahmed
2- The man him called me was Ahmed

Obviously ‘he’ sounds better than ‘him’ in this sentence. So your answer is ‘who’

I hope this helps you out in the future