The Meselson-Stahl experiment provided the first experimental evidence that: A. Newly synthesized DNA in E. coli has different nucleotide sequence than the parent DNA. B. DNA synthesis in E. coli proceeds by a conservative mechanism. C. DNA polymerase is required for DNA synthesis. D. DNA synthesis in E. coli proceeds by a non-conservative mechanism. E. DNA synthesis requires dATP, dCTP, dGTP, and dTTP. F. DNA synthesis in E. coli proceeds by a semi-conservative mechanism.