The correct order of dipole moment is: (A) CH4 < NF3 < NH3 < H2O (B) NF3 < CH4 < NH3 < H2O (C) NH3 < NF3 < CH4 < H2O (D) H2O < NH3 < NF3 < CH4

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The correct option is (A): $$\mathrm{CH}<em>{4} < \mathrm{NF}</em>{3} < \mathrm{NH}<em>{3} < \mathrm{H}</em>{2}\mathrm{O}$$

Here, the dipole moments of the molecules are as follows:

• Methane ($\mathrm{CH}_{4}$): 0 D
• Nitrogen trifluoride ($\mathrm{NF}_{3}$): 0.2 D
• Ammonia ($\mathrm{NH}_{3}$): 1.47 D
• Water ($\mathrm{H}_{2}\mathrm{O}$): 1.85 D

Given these values, the order of increasing dipole moment is: $$\mathrm{CH}<em>{4} < \mathrm{NF}</em>{3} < \mathrm{NH}<em>{3} < \mathrm{H}</em>{2}\mathrm{O}$$