Define hybridisation ?

Which of the following statements is not correct regarding hybridisation ?

With the help of VBT explain the hybridisation in tetracarbonyl nickel and sketch the shape of the complex.

Name an animal which is the progeny of interspecific hybridisation between donkey and horse.

Mule is a progeny obtained by interspecific hybridisation. Who are the parents of mule?

Explain the hybridisation, geometry and magnetic property of [Ni(Cl)_(4)]^(2-) .

Explain the hybridisation, geometry and magnetic property of [CoF_(6)]^(3-) based on VBT.

Differentiate out-crossing, cross-breeding and interspecific hybridisation.