Which of the following action(s) make(s) capital markets more efficient? Choose all correct answer(s). a. Fund managers study patent applications filed by semiconductor manufacturers to identify good investment opportunities and purchase their stocks before these companies announce good news. b. Fund managers study companies' audit reports to identify possible financial frauds and short sell stocks of companies that are highly likely to be fraudulent. c. After 2008, financial regulators introduced new rules to limit the amount of capital that investment banks can use to trade securities. d. Dividend imputation credits attached to New Zealand shares can only be used by New Zealand tax residents.