What the difference between a "Business strategy" and a "Corporate strategy"?

a$)$corporate strategy is for big companies although a business strategy is for small companie

B$)$Business strategy applies to commercial firms while corporate strategy applies to any kind of organization

c$)$No difference

D$)$A corporate strategy applies to multi$-$business firms while business strategy applies to single business firms or to a segment in a multi$-$business firm