Derrick, a finance graduate, has joined an accounting firm. The firm opens a bank account for him in which his salary gets automatically deposited. He receives a modest but consistent amount of interest on the deposited amount. He does not use the money from the account for his daily expenses but keeps it aside to cover major future expenses. In the context of this scenario, which of the following accounts has the firm opened for Derrick?
A. A concentration account
B. A basic checking account
C. A fixed deposit account
D. A savings account