Answer:
Option D. All of the above.
Step-by-step explanation:
The reason is that time and motion studies is basically about scientific engineering and is helpful in increasing the efficiency. Hence is can be used for setting direct labor standards.
Furthermore, continuous improvement model would be used for looking at processes that will be helpful in increasing the efficiency. So taking account of such type of future efficiency gain can be helpful in setting standards.
Benchmark in the industry or of a competitor can also be used to set standards.
Hence all of the options are correct.