The immediate cause of its fall was pressure by the Ottoman Turks. ... In 1204, the Fourth Crusade conquered Constantinople, partly because the Venetians wanted to eliminate the Byzantines as competition in trading matters. Hope this helps 
 
        
             
        
        
        
Answer: B. Great Britain and France abandoned the policy of German
appeasement
Explanation: This is because Neville Chamberlin always tried to maintain peace with Hitler by giving in to his desires, or appeasement. After Hitler invaded Poland, Britain and France cut all ties with Germany and declared war.
 
        
             
        
        
        
Domestic trends
There was an increased surge of nationalism in countries in Europe such as Spain under Franco, Italy under Mussolini and Germany under Hitler, which fueled dictatorial war ambitions. the financial conditions that hit the USA and European countries created conditions for hostility and conspiracies.
Foreign policy trends
increased imperialistic desires from European imperial powers and Japan increased tensions the weakness of the league of nation and the refusal of the usa to join it weakening it furtherthe formation of alliances also fueled tensionsthe policy of allied powers led by Neville chamberlain,called appeasement policy served to give the axis powers to prepare for war.
        
             
        
        
        
Mali had acquired a reputation as a fabulously wealthy empire, ruled by a generous and pious sultan, Mansa Musa.He had expanded his boundaries all sides and acquired the cities of Gao and Timbuktu. The kingdom was considerably rich in gold. Mansa Musa also producing  controlled the salt  producing areas.
        
                    
             
        
        
        
The answer is B (Regional Lords).
Hope this helps :)