Final answer:
The C-H bond is the least polar bond among the options listed because it has the smallest difference in electronegativity between the bonded atoms, which is less than 0.5, classifying it as a nonpolar covalent bond.
Step-by-step explanation:
The bond among the given options that is the least polar is the C-H bond. This is because the difference in electronegativity between the carbon atom (approximately 2.55) and the hydrogen atom (approximately 2.20) is quite minimal, roughly 0.35. According to the electronegativity guidelines, a bond is considered nonpolar covalent if the difference in electronegativities is less than 0.5.
When discussing bonds, the polarity of a bond is determined by the difference in electronegativity between the two atoms. The C-O, P-F, and C-F bonds are more polar than the C-H bond, with C-F being the most polar due to the large electronegativity difference between carbon and fluorine. The C-As bond is more polar than the C-H bond but less polar than the C-O, P-F, or C-F bonds due to arsenic's electronegativity being closer to that of carbon.
However, since C-H has the smallest difference in electronegativities and falls below 0.5, it is correctly labeled as a nonpolar covalent bond, making it the least polar option among those provided.