The Amber Mutations Initially Discovered by Sydney Brenner and Colleagues

The amber mutations initially discovered by Sydney Brenner and colleagues was eventually shown to include a(n) :

A) unusual amino acid that generated an amber color in the affected bacteria.
B) premature stop codon within the gene's open reading frame.
C) insertion mutation that creates a translational frameshift.
D) previously unknown signal for speeding the translation process.
E) a deletion mutation that creates a translational frameshift.