The RNA sequence below depicts the part of a 330 nucleotides long mRNA and it encodes the C-terminal portion of a protein.
5'-... ... ... AAC ACC ACG ACC CAU GUG GCG AGA CGG UAG-3'
A mutation was identified in this RNA denoted as \(322A \rightarrow U\). This nucleotide change is represented by which of the following class(es) of mutation?