Capability maturing model is a$($n$)\_\_\_\_\_\_\_\_\_\_\_\_\_.$

a$.$

structured process to estimate the development costs of an organization's software development projects.

b$.$

approach to identify user friendliness of an organization's software products.

c$.$

methodology that assess the quality of an organization's products.

d$.$

process$-$improvement approach $($useful for but not limited to software engineering projects$)$ that can assist in assessing the maturity, quality, and development of an organization's development processes, and suggest steps for their improvement.