Auto Categorization of Expenses

I am looking for a way to automate the categorization of a running list of expenditures.

So in column B I have expenses listed (auto imported directly from financial institutions) and in column C I have a data validation drop down.
Is there a good way to auto populate the category drop down in Column C for some of the more common items in Column B?

For instance:
if Column B contains the text "transfer to", fill corresponding cell in column C with the drop down "Transfers". Or if Column B contains the text "Paycheck", fill corresponding cell in column C with "Income".