What is the relationship between 'eurozone' and 'euro' in the context of the input sentence.
Options: brand, manufacturer, currency, creator

"However, if it increasingly looks like the economic hit to the rest of the eurozone from a Greek exit was being contained (by the various firewalls that have been put in place in recent years, and the fact that Greece only accounts for some 2pc of eurozone GDP), sterling’s gains against the euro would likely be limited."
currency