Which characteristic is unique to cephalopods? They have a radula. They can live in water or on land. They have a closed circulatory system. They can produce pearls.

Option C, They have a closed circulatory system

Explanation:

Cephalopods belong to phylum Mollusca and are unique in sense that they have a closed circulatory system. This closed circulatory system consists of three unusual hearts with arteries, veins, and capillaries. Excepts Cephalopods, all majority of mollusks have open circulatory system. In open systems, heart pumps blood through blood vessels into the gills and then into body cavities (hemocoels)

Hence, option C is correct

Given :

Some compounds :

.

To Find :

Which of the following compounds has the most deshielded protons .

Solution :

Deshielded means nucleus whose chemical shift has been increased due to removal of electron density, magnetic induction, or other effects .

In simple words deshielding means the ability to shift protons .

Now , among Cl , I , Br and H . Cl is the most electron negative .

Therefore , deshielding will be more in .

Hence , this is the required solution .