Task: Question Answering
Input (English): Problem: the ratio, by volume, of soap to alcohol to water in a certain solution is 20: 50: 80. the solution will be altered so that the ratio of soap to alcohol is doubled while the ratio of soap to water is halved. if the altered solution will contain 100 cubic centimeters of alcohol, how many cubic centimeters of water will it contain ?
Options: a. 520, b. 640, c. 700, d. 750, e. 800
Output (English): b