Take context from the input text and decide on the accurate relationship between 'smelting' and 'metal' from the options provided.
Options: director/manager, product/material produced, distributed by, publisher

Keller Rohrback has also handled environmental litigation involving home heating oil, contaminated drinking water, contaminated sediments, landfill leachate, metal smelting and finishing wastes, tank farms, chemical plants, gas stations, and major manufacturing concerns.
product/material produced