An atomic mass unit is a unit of measurement that is used to measure the mass of atoms. The atomic mass unit (abbreviated: amu or u) is roughly equal to the mass of 1 proton<span> or 1 neutron. The unified atomic mass unit and the dalton are different names for the same thing. The dalton name is used more over time.</span>
I think it’s A because each unit is worth 3
The Yellow Book. The yellow book is the object that reflects light with the longest wavelength. In the visible spectrum the color with the shortest wavelength is violet while the longest is red