Can someone explain how to get the answer providing formulas and calculations? Thank you

151) The balance sheet of Subsidiary Co. shows assets of $86,400 and liabilities of $15,000. The fair value of the assets is $90,000 and the fair value of its liabilities is $15,000. Parent Co. paid Subsidiary S95,000 to acquire it. Parent should record goodwill on this purchase of A) $23,600. C) $3,600. B) $20,000. D) $5,000