According to the resource$-$based view $($RBV$)$ of competitive advantage, which four critical attributes must a firm's exploitable resources possess to ensure sustainable competitive advantage?

a$.$ Tactical efficiency, strategic alignment, economies of scale, extensive distribution networks

b$.$ Inventory turnover rates, high profitability, extended accounts payable, strategic partnerships

c$.$ Low overhead, rapid fulfillment, robust infrastructure, adaptability

d$.$ Rareness, value, imperfect imitability, non substitutability

e$.$ Digital presence, mobile application, cloud infrastructure, skilled IT personnel