gstr3b credit note entry table ?

I received some goods against invoice by a supplier. Due to wrong design i sent it back.
Supplier issued credit note to me for that invoice.

In my gstr3b :

1. Will cn  be entered as a itc reversal , if yes under which table ?

Or

2. Should i deduct that cn gst amount from my monthly itc and quote the resulting amount directly in 4a (5).