Answer

in multicellular organisms tissues combine to form:

a. organs

b. an organism

c. organ systems

d. cells

organs which then combine to make an organ system and finally the organism. The cell is the smallest off all the 4 options

Explanation:

tissues combine to form organs

Explanation: Molecules combine to form cells, cells combine to form tissues, tissues combine to form organs, organs combine to form organ systems, and organ systems combine to form organisms

c. live where it’s cold and icy