Which mRNA base sequence would produce amino acid chain His-Ser-Arg?

To produce the amino acid chain His-Ser-Arg, the corresponding mRNA codons would be: CAU for histidine (His), UCU for serine (Ser), and CGU for arginine (Arg). Therefore, the mRNA base sequence that would produce this amino acid chain is 5'-CAU UCU CGU-3'. This sequence would be translated into the specified amino acids during protein synthesis.