Which of the following is at the core of the Blue Ocean strategy perspective?

a$.$

Possessing a small number of unique and difficult to copy competencies that enable the firm to do things others can not

b$.$

Choosing a position in an industry and then aligning all the activities in the firm to that choice

c$.$

Seeking a series of resource advantages. As competitors match an advantage the firm has moved on to a new source of advantage

d$.$

Looking across and challenging existing industry boundaries to create uncontested market space