Can you help me please

Which list shows the levels of organization of an organism in hierarchical order from left to right, from the smallest to the most complex?

The observations of hooke and van leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? a. the cell theory stating that all living things are composed of cellsb. the theory of spontaneous generation, which held that life forms could arise spontaneouslyc. the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organismsd. the germ theory of disease and causative agents

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism