What is the difference between an ethnocentric and a polycentric staffing approach?

a$.$ An elhnocentric staffing approach may be more expensive than a polycentric staffing approach.

b$.$ An ethnocentric steffing approach alleviales cultural myopia, while a polycentric staffing approach can lead to cullural myopia.

c$.$ An elhnocentric steffing approach seeks host$-$country nationals for all key positions, while a polycentric staffing epproach seeks the best people for key jobs regardless of nationality.

d$.$ An elhnocentric staffing approach is now used in most international businesses, while the polycentric staffing approach is waning.