Which of the following are valid reasons for a firm not using objective techniques?
i. Data may not be available.
ii. Cost estimates are sufficiently accurate for the firm's purposes.
iii. Accountants may be ignorant of appropriate techniques.
iv. The firm gives low priority to cost estimation.

A) i and ii
B) i, ii and iii
C) ii, iii and iv
D) i, ii and iv

Both options i and ii provide valid reasons for not using objective techniques. Option iii is not a valid reason as it implies a lack of knowledge rather than a specific reason for not using objective techniques. Option iv is also a valid reason as a firm may prioritize other aspects of their operations over cost estimation. Therefore, choices i, ii, and iv are the best answer.