In the absence of a cybersecurity theory, we have security standards, frameworks and best practices. An example of best practices is: a. to use a password of a certain composition and strength, such as minimum 8 characters
b. to specify the use of NIST cybersecurity framework for Federal Government computers
c. to have product specs written by vendor on every security product or in a document
d. to use Cisco Security Framework

a. to use a password of a certain composition and strength, such as minimum 8 characters.

Explanation:

Cyber security can be defined as preventive practice of protecting computers, software programs, electronic devices, networks, servers and data from potential theft, attack, damage, or unauthorized access by using a body of technology, frameworks, processes and network engineers.

In the absence of a cybersecurity  theory, we have security standards, frameworks and best practices.

An example of best practices in cybersecurity is the use of a password of a certain composition and strength, such as minimum 8 characters. This would ensure there's a formidable wall to protect data and an unauthorized access or usage of the system network.

The correct option is;

b. To specify the use of NIST cybersecurity framework for Federal Government computers

Explanation:

The NIST cyber security framework comprises guidelines, guidance and best practices developed to the cybersecurity of critical infrastructure thereby minimizing cyber risks and enhancing reliability of vital infrastructures

The framework is a non-mandatory requirements developed by NIST in collaboration with industry stakeholders that considers, cost-efficiency adaptability and repeatability as being of primary importance.