Refer to the input text as context and select the correct relationship between 'Mozal' and 'Maputo' from the available options.
Options: chief executive officer, platform, headquarters location, distribution format

The BHP Billiton Mozal smelter, for example, consumes two-thirds of the electricity generated in Mozambique but employs only 1,070 people at its plant in Maputo and 3,500 downstream, with jobs ranging from catering to sewing uniforms, according to its own figures.
headquarters location