Eukaryotic DNA is present in nucleus. Primary transcript synthesized in nucleus during transcription undergoes processing to produce a functional mRNA and is transported to cytoplasm where it serves as template for amino acid sequence of polypeptide, synthesized during protein synthesis/ translation. Thus, gene regulation in eukryotes can occur at transcriptional, post- transcriptional, translational, post- translational levels. First two events are controlled by nuclear genes and last two are governed by nuclear as well as other genes (cytoplasmic). Correct answer is C.