Step 1: In this specific transamination reaction, think of alanine as the amino donor and oxaloacetate as the amino acceptor keto acid.
Once alanine passes its NH2 group over to oxaloacetate through the enzyme alanine aminotransferase, alanine is left as pyruvate, its corresponding keto acid form.
Oxaloacetate, having accepted that amino group, is converted into aspartate, so the pair of products is pyruvate and aspartic acid, not malic, fumaric or glutamic acid which belong to different metabolic reactions. Answer: Aspartic acid.