The product of prime factors of 54 is

Product of prime factors of a number is its standard form

Standard form of $N\left(>1\right)=P_1{}^{n_1}.P_2{}^{n_2}.P_3{}^{n_3},\mathrm{....}$

Product of prime factors of  $54=2\times 3\times 3\times 3=2^1\times 3^3$ .

So option ‘C’ is correct.