All of the following at one time had control over an essential resource that served as a barrier to entry except

A) DeBeer's Diamond Company
B) Standard Oil Company
C) International Nickel Company of Canada
D) IBM

Barrier To Entry

Factors that make it difficult for new firms to enter an industry.

Essential Resource

A fundamental input required for the production process or for maintaining the well-being of individuals, often considered critical for economic development and sustainability.