What is the relationship between 'iPhone' and 'Foxconn' in the context of the input sentence.
Options: business division, manufacturer, location of formation, legal form

By the end of the year, according to Reuters, BYD should have 10 GWh of battery production capacity, which it expects to increase to 34 GWh by 2020 with a new factory in Brazil—about the same capacity as Tesla’s.Other Tesla rivals rushing to the battery production scene will be iPhone manufacturer Foxconn and LG Chem, which is already one of the top three battery makers.
manufacturer