Give a scientific reason: Annelids are considered evolutionary precursors of molluscs.

(N/A) Annelids are considered evolutionary precursors of molluscs due to several key pieces of evidence:
$1$. The presence of a $trochophore$ larva in both groups indicates a common ancestry.
$2$. The $trochophore$ larva of molluscs is structurally very similar to that of annelids.
$3$. While molluscs have lost the metameric segmentation characteristic of annelids,the larval development stages provide a strong link between the two phyla,suggesting that molluscs evolved from an annelid-like ancestor.