After touring a coffee bean farm, Nate impulsively bought 8 bags of coffee beans. Of the bags he bought, 5 were filled with amaretto flavored coffee beans. If Nate randomly selects 4 of the bags to send to family members, what is the probability that all of them are amaretto flavored?

a) ³/₈
b) ⁵/₁₂
c) ¹/₁₂
d) ¹/₄