Concerning Producing Larger Organisms Without Cellular Differentiation

Concerning producing larger organisms without cellular differentiation,

A) nature has never evolved larger organisms because it would never work.
B) nature has evolved larger unicellular organisms but they are rare and have surface-to-volume limitations.
C) this has never occurred since the ancestral cell was small.
D) the more derived the organism,the more differentiated and the smaller the cell size.
E) the more primitive the organism,the smaller the cell size.Larger size and complexity is accomplished through multicellularity.A workable surface-to-mass ratio in an increasingly large single cell cannot be maintained.