The correct option is
B Arrested
A synonym is a word/phrase that means the same as another word/phrase.
Option B: The word 'captured' means 'take into one's possession or control by force'.
'Arrested' means 'take someone (forcibly) by legal authority and take them into custody'.
As you can see, 'arrested' means the same as 'captured'.
Both mean 'to take someone into possession/custody by force'.
Hence, 'arrested' is the synonym of 'captured'. Hence, option B is correct.
Option A: 'Released' means the opposite of 'captured'. It means 'to set someone/something free'.
Option C: 'Arrived' means 'to reach a place at the end of a journey'.
Option D: 'Returned' means 'to go back to a place or person'.
These words do not mean the same as 'captured'.
Hence, options A, C and D are wrong.