This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
To get the product 1 , we should multiply 8/21 by 21/8 i.e (c).

Hope this may helps uu.........
To get the product 1, we should multiply 8/21 by 21/8 (c)
because the product of any number with its reciprocal results 1.
So, the option (c) 21/8 is the answer.
1 5 1