Questions

For “Pay for” means give money to someone for goods received. So, it is the phrasal verb which will make the sentence grammatically correct, as the sentence talks about paying money for buying certain articles. Pay out means the act of receiving money or material gain as a compensation. Pay off means to pay a debt. Pay of has no meaning.

Loktak Lake:the largest freshwater  (sweet)  lake  in  North -East  India,  also  called  the  only Floating  lake  in  the  world  due to the floating phumdis (heterogeneous mass of vegetation,    soil,    and    organic matters    at    various    stages    of decomposition)   on   it,   is   located near   Moirang   in   Manipur   state, India.  The  etymology  of  Loktak  is Lok  =  "stream"  and  tak  =  "the end"