(A) According to the article "Is a Share Buyback Right for Your Company?", how did the common wisdom explain the positive impact of buyback on the share price? What are the two ways the author thinks buybacks affect a firm's value? What are the three situations in which the author explains a buyback announcement can send a negative signal? (B) The author argues that many companies underestimate how many shares they need to buy back to send a credible signal to the markets. He set up the following table of materiality levels for share buybacks. Based on this table, how many shares (in percentage term) will a firm have to buy back in order to hit the trigger materiality level (that is, at least 5% ) if its shares are trading at a 30% discount to their real value