What is the most likely reason that nations raised tariffs in imports during the great depression

They wanted to increase the sales of their own products.  In order to stimulate their economy, they concentrate on buying goods and services in their countries.  It was not the time to patronize imports because getting more imports would further harm the economy.  So they limited trade through tariffs. 

c. the passage of the fifteenth amendment

a overment ran by a signle strong leader is also known as multiple things depending on the country and the coutnrys belifs and relgions

president,dictator