Answer:
Correct answer is 3.Dorians .
Explanation:
Correct answer is Dorians, because with the migrations of Dorians from north to Peloponnesian peninsula a period of Dark Ages started. This is period is known as dark because we practically have no written sources from it.
First option is not correct as dark age started after the collapse of this civilization.
Second option is not correct as Minoan civilization disappeared before the emergence of Minoan civilization.
Last option is also not correct as Phoenicians were not connected with Greek dark ages.