The correct option is D 2, 6, and 6.5
(5, 3, 4) is a Pythagorean triplet.
⇒ (2.5, 1.5, 2) is also a Pythagorean triplet.
(5, 12, 13) is a Pythagorean triplet.
⇒ (10, 24, 26) is also a Pythagorean triplet.
⇒ (2.5, 6, 6.5) is also a Pythagorean triplet.
⇒ (2, 6, 6.5) is not a Pythagorean triplet.