Which of the following statements is true of managerial accounting? 

a). Managerial accounting is required to be reported annually, also may be reported monthly or quarterly. 

b). Managerial accounting provides information to the external stakeholders of the company. 

c). Managerial accounting is primarily concerned with generating information for use by managers. 

d). Reporting under managerial accounting is constrained by rules such as generally accepted accounting principles.