If the statements above are true, which of the following conclusions is best supported by them? A. If care is taken in planning the computer system to be used for defense against attack by ballistic missiles, there is a high probability that the defense system will be successful if and when it is needed. B. Methods for reducing errors in constructing large-scale computer systems will not be found. C. A defense against ballistic missile attack will not work successfully when it is first called on. D. Some means for control other than a large-scale computer system will have to be found for a system for defense against ballistic missiles. E. A defense against attack by ballistic missiles cannot be assured of success the first time it is used.