请教V2 习题

Which of the following is most likely to result from an increase in the dividend tax credit？
A. Increase in price of Canadian dividend-paying shares
B. Decline in price of mutual funds with preferred share investment mandates.
C. Decrease in disposal income of retired Canadians.
D. Increase in proportion of Canadian taxes paid from investment income.

个人的理解是dividend tax credit 是给予shareholder减少对于dividend的税，也就是说shareholder的个人可支配收入会升高，所以C是反的
但是另外三个选项不太明白，请求解析一下。谢谢。