The following cell structures are located within cells that make proteins. Which description best explains the relationship among these cell structures in making a protein?
• nucleus
• ribosome
• endoplasmic reticulum (ER)

A. ER creates proteinDNA in the nucleus codes for ribosomes to surround proteinfolds into its active shape
B. nucleus makes proteinwinds through the ERprotein folds into its active shape
C. DNA in nucleus codes for proteinassembled in ribosomes and moves to ERprotein folds into its active shape
D. the nucleus directs ER to assemble the proteinribosomes surround proteinfolds into its active shape