What do ribosomes produce following instructions from the nucleus?
A. energy
B. proteins
C. DNA

 Here's what I could find:

Ribosomes get their orders for protein synthesis from the nucleus, where portions of DNA (genes) are transcribed to make messenger RNAs. An mRNA travels to the ribosome and uses information it contains to build a proteins with specific amino acid sequences.

Explanation: I'm pretty sure it's protein, if not then it's DNA.

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.