The correct answer is: marsupials.
Marsupials are actually defined by their ability to hold the young in the pouches, where they can be well protected. Some examples are Kangaroos and Koalas.
Other answers are wrong: for example, gymnosperms are plants, not animals.
Cardiac muscle tissue or myocardium
Explanation:
Unicellular organisms contain one cell and all of their functions are based on that one cell whereas multicellular organisms contain more than one cell and there functions are divided amongst different cells like nervous cells, cardiac muscle cells etc..
Unicellular organisms are composed of a single cellMulticellular organisms are composed of more than one cellSimple body organizationComplex body organizationA single cell carries out all necessary life processesMultiple cells perform different functionsThe total cell body is exposed to the environmentOnly the outer cells are exposed to the environmentDivision of labour is at the organelle levelDivision of labour is at cellular, tissue, organs and organ system levelIncludes both eukaryotes and prokaryotesIncludes only eukaryotes
