Question

1. I like your pants. Where did you buy them?
2. I like your pants. Where did you buy these?
3. I like your pants. Where did you buy those?
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#1 is correct. By the way, can we refer to 'pants' as 'these' or 'those' as in #2 qand #3?

Answer 1

Yes, you can use all 3 phrasings. 1 and 3 are best, but all are correct.