To understand whether todays stock return can be predicted by the stock return of the last trading day, Jerry has performed the runs test using the market indices of four different countries: A, B, C, and D. The table below shows the number of runs observed and the number of runs expected for the daily interval of each country.

Country	Actual number of runs	Expected number of runs
A	831	825
B	670	720
C	950	910
D	740	743

According to Jerrys results, answer the following questions.

(a) Explain which countries are more likely to violate the weak-form market efficiency.

(b) Which of the countries in (a) provides strong evidence that suggests todays stock return is positively related to the stock return of last trading day? Explain your answer.