Let $d_1, d_2, \ldots, d_k$ be all the factors of a positive integer $n$ including 1 and $n$. If $d_1 + d_2 + \ldots + d_k = 72$, then $\frac{1}{d_1} + \frac{1}{d_2} + \cdots + \frac{1}{d_k}$ is:\\
(A) $\frac{k^2}{72}$\\
(B) $\frac{72}{k}$\\
(C) $\frac{72}{n}$\\
(D) none of the above