Which of the Following Best Explains 'Resource-Dependency Theory

Which of the following best explains 'resource-dependency theory'? 

A)  Business success is primarily achieved through deploying a company's external resources. 
B)  Business success is primarily achieved through deploying a company's internal resources. 
C)  Business success is primarily achieved through efficiency gains. 
D)  Business success is primarily achieved through deploying a company's external and internal resources.