2. A fair die (it is a cube toy with points numbered $1,2,3,4,5,6$ on each face) is thrown 3 times. The probability of at least one 6 facing up is
A. $\frac{5}{216}$
B. $\frac{25}{216}$
C. $\frac{31}{216}$
D. $\frac{91}{216}$
2. $\mathrm{D}$ appears at least once with 6 points upwards. The opposite is that 6 points do not appear upwards, so the probability is $1-\frac{5^{3}}{6^{3}}=\frac{91}{216}$.