Correct Response: D. When designing precision parts, engineers generally specify engineering tolerances, the permissible limits in variation of specified dimensions. Parts that must interact intricately with other precision parts generally have low tolerance variations so that the parts can function effectively with one another. A is incorrect because producing highly precise parts generally increases costs and makes mass production less feasible. B and C are incorrect because designing a part to last a long time and to withstand high levels of stress is likely to have more to do with the type of materials used than with how closely the part must match the design specifications.
