Answer B. Smith (2009) found that elephants have teeth.
Explanation: The APA style of referencing is a process whereby referencing is done using the name of the author first and the date written in parenthesis. That is the year of publication. This "Smith (2009) found that elephants have teeth" shows that it is citated in a write up. But when referencing at the end of your work, you cite the name of the author/s in full, year of publication, and the page or pages quoted from.