Take context from the input text and decide on the accurate relationship between 'Ausgrid' and 'Sydney' from the options provided.
Options: currency, headquarters location, director/manager, distribution format

For households in the area served by Ausgrid - the inner city, eastern and the northern suburbs, extending to Newcastle - the difference between the highest and lowest offers is $400, with the difference between the highest and lowest a more modest $285 in western and southern Sydney and also Wollongong, which is the area served by Endeavour Energy.
headquarters location