which of the following is an example of a polar molecule\nwater\npropane\nmethane\ncarbon dioxide

Brief Explanations:

A polar molecule has a net dipole moment due to unequal sharing of electrons and an asymmetrical shape. Water ($H_2O$) has a bent geometry; oxygen is more electronegative than hydrogen, creating partial charges, and its asymmetrical shape results in a net dipole moment. Propane ($C_3H_8$), methane ($CH_4$), and carbon dioxide ($CO_2$) are nonpolar: methane and propane have symmetrical tetrahedral/alkane structures with no net dipole, while $CO_2$ is linear, so its bond dipoles cancel out.

Answer:

water