Both statement I and statement II are correct. ‌ Boiling point of ‌n‌-pentane ‌‌=309K ‌ isopentane ‌‌=301K ‌ neopentane ‌‌=282.5 As branching increases molecules attain the shape of a sphere results in smaller area of contact thus weak intermolecular forces between spherical molecules, which are overcome at relatively lower temperature. Leading to decrease in boiling point.