Correct Answer: (B) 6
The product 15×14×⋯×1 represents 15!15!15!. By Legendre's formula, the highest power of prime 3 dividing 15!15!15! is given by E3(15!)=⌊153⌋+⌊159⌋=5+1=6E_3(15!) = \lfloor 153\frac{15}{3}315 \rfloor + \lfloor 159\frac{15}{9}915 \rfloor = 5 + 1 = 6E3(15!)=⌊315⌋+⌊915⌋=5+1=6. Alternatively, counting powers of 3 among multiples in the product: 3 (one), 6 (one), 9 (two), 12 (one), and 15 (one) gives 1+1+2+1+1=61 + 1 + 2 + 1 + 1 = 61+1+2+1+1=6. Thus, the maximum value of mmm is 6.