Which of the following increases homozygosity?

Inbreeding increases homozygosity. Outbreeding increases heterozygosity.In inbreeding, mating of more closely related individuals within the same breed for 4-6 generations is done. So increase in homozygosity is possible. In outbreeding, mating is done between unrelated animals which may be between individuals of the same breed but having no common ancestors for 4-6 generations (outcrossing) or between different breeds (cross breeding) or different species (interspecific hybridisation).