Which one of the following statements concerning technical indicators is true? a) the stock market is considered weak when market volume falls during a market decline. b) the market is considered strong as long as the number of stocks that advance in price on a given day is less than the number that decline. c) the market is expected to continue along its current trend when there is little difference between the volume of odd-lot purchases and sales. d) the market is expected to increase immediately when the volume of short sales begins to rise.