The correct answer is their blood lacks A or B antibodies.
People with type AB blood have A and B antigenes on the surface of red blood cells (RBCs). Antigen AB has no antibodies, thus, transfusion can be considered safe ( the serum of the recipient does not contain antibodies for the blood cell antigens of the donor).
Muscles and internal organs
The Americans colonies became free and independent states explanation: because they declared independence
With the actions of the humans the biodiversity is facing a huge problem in most of the world, the habitats are destroyed, forests are cleared, animals are killed, water and air are polluted...
In order to conserve the biodiversity there are certain things that have to be put in action. The methods for conservation can be in-situ methods and ex-situ methods.
The in-situ methods are the preferred ones, as these methods are focused on conserving the environment as it is. This basically means that the ares that have larger biodiversity, and especially where there's species that are rare, should be made national parks, sanctuaries, monuments of nature, thus being protected by law.
The ex-situ methods are the ones that involve the conservation of the species outside of their natural habitat. That is done with gene banks, sperm and ova banks, seed banks, zoos and botanical gardens, collections of In vitro plant tissue and microbal culture, and captive breeding of animals and artificial propagation of plants.
