In the context of the input sentence, determine the relationship between 'Apple Inc' and 'iPhone'.
Options: product/material produced, location of formation, founded by, headquarters location

The housing index (.HGX) rose 1.64 percent on the data, outperforming the overall stock market, which fell after Apple Inc (AAPL.O) late on Tuesday gave a fourth-quarter revenue forecast that fell short of estimates and missed some targets for iPhone sales.
product/material produced