Which of the Following Pairs of Siblings Is Most Likely

Which of the following pairs of siblings is most likely to have the closest, warmest relationship?

A) ​Yarone is 13 years old, and his younger sister Shayla is 8 years old.
B) ​Tiffany is 5 years old and her younger brother Tajuan is 4 years old.
C) ​Marquis is 9 years old and is very laid back, and his brother, Lanom, is 7 years old.
D) ​Jack and his sister Jill are fraternal twins, and where Jack is very mellow his sister tends to be very emotional.