You're the manager of a factory that produces enzyme-washed blue jeans (the enzymes lighten the color of the denim, giving a "faded" appearance). When the most recent batch of fabric came out of the enzyme wash, however, the color wasn't light enough to meet your standards. Your quality control laboratory wants to do some tests to determine why the wash enzymes didn't perform as expected. Based on your understanding of enzyme structure, which of the following would you recommend that they also investigate?

The amino acid sequence needs to be changed slightly to ensure a more stable tertiary structure

Explanation:

the primary structure, amino acid sequence should be adjusted a bit  to give a stable 3-D structure in tertiary protein, needed for precise active sites for the enzyme to aid fading.

Explanation:

The specificity of an enzyme depends on the precise shape of its active sites.The shape of enzyme active sites, depends on the 3-Dimensional structure of tertiary protein. Furthermore , the sequence of arrangement of amino acids in primary and secondary proteins and the interactions of these with disulphide bridges and interactions ensures stable tertiary structure needed for 3-D shape of Active site of enzyme.

Therefore, the active sites for  enzymes used  for washing in this question  are not precise with the substrates on the Denim jeans, and therefore failed  to form enzyme-substrate complex needed for enzyme-product complex, therefore failed to give lighten the color.

Thus the primary structure, amino acid sequence should be adjusted  to give a stable 3-D structure in tertiary protein, needed for precise active sites for the enzyme to aid fading.