Which document is an excellent reference for security managers involved in the routine management of information security?

a. SP 800-12, “An Introduction to Computer Security”
b. SP 800-14, “Generally Accepted Principles and Practices for Securing Information Technology”
c. SP-800-30 Rev. 1: “Guide for Conducting Risk Assessments”
d. SP-800-50: “Building an Information Technology Security Awareness and Training Program”