Final answer:
A substitution mutation likely caused the single amino acid change in the protein, as addition and deletion mutations tend to result in frameshifts that alter the whole amino acid sequence beyond the point of mutation.
Step-by-step explanation:
If a mutated DNA sequence produces a protein that differs by one central amino acid from the normal protein, the kind of mutation that likely occurred is a substitution mutation. A substitution mutation involves the exchange of one base for another, which can change a single codon and result in the placement of a different amino acid at a specific location in the protein. This change can lead to minor or major functional changes in the protein, depending on the role of the affected amino acid.
Addition mutations (insertions) and deletion mutations generally lead to frameshifts, which change the reading frame of the mRNA and usually result in a completely altered amino acid sequence from the point of mutation forward, often resulting in a non-functional protein. Since the question specifies only a single amino acid change, frameshifts are less likely to be the cause unless they are immediately counteracted by an opposing mutation (an insertion followed by a deletion or vice versa), which is rare.