Question

protein synthesis is...
the process of using proteins to build dna in cells.
the process of using proteins to build rna in cells.
the process by which proteins are built in cells.
the process by which fat is made in cells.

Explanation:

Protein synthesis is the biological process where cells build proteins. DNA is used to make RNA (transcription), and then RNA is used to make proteins (translation). Options 1 and 2 have the wrong direction (proteins are not used to build DNA or RNA in protein synthesis). Option 4 is about fat - making (lipogenesis), not protein synthesis.

Answer:

the process by which proteins are built in cells.