Take context from the input text and decide on the accurate relationship between 'Carlos Ghosn' and 'Nissan' from the options provided.
Options: currency, position held, owned by, employer

However last week’s announcement saw claims that chief executive Carlos Ghosn had been "scaremongering" when he warned that the prospect of Britain leaving the EU or renegotiating its membership terms would cause Nissan to “reconsider” its investments in the UK.
employer