Analyze the relationship between 'Norsk Hydro' and 'aluminium' within the context of the input sentence.
Options: product/material produced, operator, owned by, distributed by

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.
product/material produced