DBMS, BCNF DOUBT

Question

Consider the following relational schema:

Suppliers(sid:integer, sname:string, city:string, street:string)Suppliers(sid:integer_, sname:string, city:string, street:string) 

Parts(pid:integer, pname:string, color:string)Parts(pid:integer_, pname:string, color:string) 

Catalog(sid:integer, pid:integer,cost:real)Catalog(sid:integer, pid:integer_,cost:real)

Assume that, in the suppliers relation above, each supplier and each street within a city has unique name, and (sname, city) forms a candidate key. No other functional dependencies are implied other than those implied by primary and candidate keys. Which one of the following is TRUE about the above schema?

1. The schema is in BCNF
2. The schema is in 3NF but not in BCNF
3. The schema is in 2 NF but not in 3NF
4. The schema is not in 2NF 

Here is the link:-https://gateoverflow.in/43474/gate2009-56

I cant understand this line " each supplier and each street within a city has unique name"

Comments

@srestha

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I already gave ur ans:)
Is it cleared?