Which of the following is the smallest level of organization in living things? A. organ system
B. cell
C. tissue
D. organ

B. Cell

Explanation:

Order from smallest to most complex:

Cell - Tissue - Organ - Organ system.

Cells are the smallest. Multiple cells working together forms a tissue. Multiple tissues working together forms and organ. Multiple organs form an organ system.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

i think its white blood cells

i hope this