Correct Answer - Option 3 : Ligament
Given: Petal, Sepal, Pollen, Ligament.
Logic:
Petal, Sepal, and Pollen are all the parts of a Flower.
Whereas,
Ligament is a body part of the Human Beings.
Petal: The parts of a flower that are often conspicuously colored.
Sepal: The outer parts of the flower (often green and leaf-like) that enclose a developing bud.
Pollen: a fine powdery substance, typically yellow, consisting of microscopic grains discharged from the male part of a flower or from a male cone.
Ligaments are bands of tough elastic tissue around your joints.
Hence, ligament is the odd one out.