I would say d is a safe choice unless your reading about history in which there is a lot of intolerance in someone's home country. Based on history and asking people now, most people immigrate for an overall better chance at life and I would say that being able to support your family where there is an economic opportunity is a big push. Especially because there a lot of intolerance everywhere and depending on the level, people don't necessarily leave the country altogether for it.
