Attribution is the process by which people send messages to each other across various cultures. a. true b. false

I think it's true 
 the process by which people send messages to each other across various cultures. 

If you mean how the great lakes formed, then  the great lakes began to form at the end of the last glacial period 14,000 years  ago, ice sheets  retreated, which led to exposing the basins they had carved into land which then filled with melt-water.