Final answer:
Water (H2O) is the polar molecule among the given options because of its bent structure and the unequal sharing of electrons between oxygen and hydrogen, resulting in a dipole moment.
Step-by-step explanation:
The student has asked to identify which of the given molecules is polar based on their Lewis diagrams. Among the options, H2O (c) is the molecule that is polar. This is because water has a bent molecular structure due to the two lone pairs of electrons on the oxygen atom, which leads to an unequal sharing of electrons between the oxygen (O) and the hydrogen (H) atoms. This creates a net separation of charge or a dipole moment. The oxygen side of the molecule is more electronegative, making it slightly negative (δ-), while the hydrogen atoms are slightly positive (δ+), which is indicative of a polar molecule.