Answer:
9 moles is correct
Step-by-step explanation:
Using Avogadro's constant for the definition of a mole: 6.022 × 10²³ of anything:
Number of moles = number of things (molecules) / Avogadro's constant
moles = 5.4×10²⁴ ÷ 6.022×10²³ = 8.967... ≈ 9 moles