If $\mathrm{p}, \mathrm{q}, \mathrm{r}$ are in $\mathrm{AP} ; \ell, \mathrm{m}, \mathrm{n}$ are in $\mathrm{HP} ; \mathrm{p} \ell, \mathrm{qm}, \mathrm{r} \mathrm{n}$ are in $\mathrm{GP}(\mathrm{p} \ell \neq \mathrm{q} \mathrm{m} \neq \mathrm{r} \mathrm{n})$, then $\mathrm{p}: \mathrm{q}: \mathrm{r}=$
(a) $\mathrm{m}: \mathrm{n}: \ell$
(b) $\frac{1}{n}: \frac{1}{m}: \frac{1}{\ell}$
(c) $1: 2: 3$
(d) $\mathrm{n}: \mathrm{m}: \ell$