Of the given price elasticities [ed] for market demand curves, there the one which is absolutely implausible by the vantage of standard economic theory would be one for that, across all conceivable ranges of prices: (1) ed= 0 and the demand curve is vertical. (2) 0ed>1 as well as the demand curve is relatively flat. (5) ed=∞ as well as the demand curve is horizontal.
How can I solve my economics problem? Please suggest me the correct answer.