Final answer:
The accurate statement about the cells of organisms is that the single cell of a unicellular organism carries out all functions of life, unlike multicellular organisms which have specialized cells for different functions.
Step-by-step explanation:
The correct answer is C. The single cell of a unicellular organism carries out all functions of life. In unicellular organisms, a single cell is responsible for all life processes, such as obtaining energy, growth, reproduction, and responding to the environment. These organisms can be complex despite being single-celled, having intricate structures and sometimes components analogous to organs in multicellular organisms. On the other hand, multicellular organisms show a diverse range of specialization and complexity, with cells organized into tissues, organs, and organ systems to carry out specific functions that benefit the organism as a whole. Mutual cooperation among cells of the same species led to the evolution of multicellularity according to the Colonial Theory.