Which is correct and most complete according to the text?

a. Documenting a project case study is generally a micro-level contribution.

b. Future opportunities for survey based contributions are generally not possible.

c. Models predicting the value of specific strategies are entirely lacking.

d. The subject of what should be taught to black belts has been addressed in the literature.

e. All of the above are correct.

f. All of the above are correct except

(a) and (e).