Preservation is to conserve something. It can be food preservation or wildlife preservation.
Sanctuary is a place where animals are kept free in their natural habitat. It is a facility where animals are free from the disturbance in their habitat.
Park is an area of natural or planted space developed for human recreation.
A zoo is a place where animals are kept in cages for public display.
Hence by definition, it is clear that protecting animals in their habitat is Sanctuary.
Therefore the correct answer is option B.