Read this: The second Diadochi war began following the death of Antipater in 319 BC. Passing over his own son, Cassander, Antipater had declared Polyperchon his successor as Regent. Cassander rose in revolt against Polyperchon (who was joined by Eumenes) and was supported by Antigonus, Lysimachus and Ptolemy. In 317, Cassander invaded Macedonia, attaining control of Macedon, sentencing Olympias to death and capturing the boy king Alexander IV, and his mother. In Asia, Eumenes was betrayed by his own men after years of campaign and was given up to Antigonus who had him executed.

Who did Antipater declar as his successor?
What is the answer? (If it cannot be answered, return "unanswerable")
Polyperchon