One kilogram is the mass obtained by dividing Planck's constant by—

• a$6.62607015 \times 10^{-34}$ m$^2$/s
• b$6.02214076 \times 10^{23}$ m$^2$/s
• c$1.602176634 \times 10^{-19}$ m$^2$/s
• d$1.380649 \times 10^{-23}$ m$^2$/s