Young animals approaching maturity might do which of the following to find mates or establish new territories?

A. Exponential growth

B. Logistic growth

C. Emigration

D. Immigration

A and B are true of whole populations but not individuals and they are not something that young animals can "do" - we reject these options.

C. Yes - this means that they leave the territory of their parents and search for new territories: this is the correct answer.