Norsk Hydro (LSE: NHY.L - news ) shares rose 2.8 percent, the top gainer in the pan-European FTSEurofirst 300 index, after the aluminium maker posted second-quarter operating earnings above expectations in spite of weaker metal prices.
In the context of the input sentence, determine the relationship between 'Norsk Hydro' and 'aluminium'.
Options: owned by, distributed by, product/material produced, operator