If the structure of \(Co,\, \ Ni\) and \(Cu\) is cubic close packed (CCP), the structure of \(Zn\) metal will be:

HCP

The correct answer is option 3. HCP.

Let us delve into the crystal structures of \(Co\) (cobalt), \(Ni\) (nickel), \(Cu\) (copper), and \(Zn\) (zinc).

1. Cobalt (\(Co\)), Nickel (\(Ni\)), Copper (\(Cu\)):
Cobalt, nickel, and copper all belong to the same group in the periodic table (transition metals) and exhibit similar atomic sizes. They crystallize in a face-centered cubic (FCC) or cubic close-packed (CCP) structure.
   - In an FCC/CCP arrangement, the atoms are closely packed, forming layers of spheres. Each sphere in a layer touches six neighboring spheres in the same plane, and there are three such planes stacked on top of each other.

2. Zinc (\(Zn\)):
Zinc is also a transition metal but differs from cobalt, nickel, and copper in terms of its crystal structure. Zinc crystallizes in a hexagonal close-packed (HCP) structure.

In an HCP arrangement, the atoms are closely packed in a hexagonal pattern. Each atom has six nearest neighbors arranged in the shape of a hexagon. The layers in an HCP structure are not as symmetrical as in an FCC/CCP structure.

To summarize:
\(Co\), \(Ni\), and \(Cu\) have an FCC or CCP structure.
\(Zn\) has an HCP structure.

Therefore, the correct answer to the question is 3. HCP.