Kaya Alp
Kaya Alp was, according to Ottoman tradition, the son of Kızıl Buğa and the father of Suleyman Shah, who was, in turn, the grandfather of Ertuğrul, and the great grandfather of the Ottoman Empire founder, Osman I.
Ferdinand I of Naples
Ferdinand I (2 June 1423 – 25 January 1494), also called Ferrante, was King of Naples from 1458 to 1494.
He was the son of Alfonso V of Aragon and his mistress, Giraldona Carlino.
Enrico d'Aragona
Enrico "Arrigo" d'Aragona (birth date unknown – 1478) was an illegitimate son of the King of Naples, Ferrante I of Aragon.
Despite the circumstances of his birth he was well regarded by his father and granted the title of Marchese (Marquis) of Gerace in 1473.
He was the father of Luigi (The Cardinal of Aragon) and Giovanna (The Duchess of Amalfi).
Lyon Cohen
Lyon Cohen( 1868–1937) was a Polish- born Canadian businessman and a philanthropist.
He was the grandfather of singer/ poet Leonard Cohen.
Henry Bryant (naturalist)
Henry Bryant( May 12, 1820 – February 2, 1867) was an American physician and naturalist.
He was the grandfather of Henry Bryant Bigelow.
Abd al-Muttalib
Abd al- Muttalib Shaybah ibn Hashim( c. 497 – 578) was the grandfather of Islamic prophet Muhammad.
John Westley
Rev. John Westley( 1636 – 78) was an English nonconformist minister.
He was the grandfather of John Wesley( founder of Methodism).
Fujiwara no Nagara
, also known as Fujiwara no Nagayoshi, was a Japanese statesman, courtier and politician of the early Heian period.
He was the grandfather of Emperor Yōzei.
Prithvipati Shah
Prithvipati Shah( ?–1716) was the king of the Gorkha Kingdom in the Indian subcontinent, present- day Nepal.
He was the grandfather of Nara Bhupal Shah.
Guillaume Wittouck
Guillaume Wittouck( 1749- 1829) was a Belgian lawyer and High Magistrate.
He was the Grandfather of industrialist Paul Wittouck.

Question: Who is the paternal grandfather of Enrico D'Aragona?
Answer: Alfonso V of Aragon