Why did canada want to increase its population during the mid to late 1900s a. canada wanted more workers to populate the territories b. canada needed more workers to increase industry c. canada needed people with new ideas d. canada needed a more diverse population

Canada want to increae its population during that time to Help with the constructions of the railroad.
So i believe the answer is B. Canada needed more workers to increase industry 
Back then, Canada took a lot of immigrants from China in order to expand the railroad industry (becausse the process of railroad building killed a lot of workers)

The answer to that would be prussia which would later be germany