Of the four arguments shown which ones isare valid If animal

Of the four arguments shown, which one(s) is/are valid? If animals lack copper, then their hair becomes unpigmented The animals hair is unpigmented. So the animal lacks copper. If animals lack copper, then their hair becomes unpigmented The animal lacks copper. So the animals hair becomes unpigmented. If animals lack copper, then their hair becomes unpigmented The animals hair is not unpigmented. So the animal does not lack copper. If animals lack copper, then their hair becomes unpigmented The animals do not lack copper. So the animals hair is not unpigmented.

Solution

The valid argument is

If animals lack copper, then their hair becomes unpigmented.

The animals lack copper, So the animals hair becomes unpigmented

Copper acts as a catalyst in pigment formation in animals. It accelerates the oxidation of DOPA resulting in formation of dark pigment.