Which aspect can CRISPR-Cas9 enhance in crops?

CRISPR-Cas9 technology enhances crops primarily by allowing precise edits to an organism's genome, which can lead to desirable traits, including a longer shelf life. This technique enables researchers to target specific genes associated with deterioration or spoilage, leading to modifications that help maintain the freshness and quality of crops after harvest. Crops with extended shelf life can significantly reduce food waste and improve food security, making this an important application of CRISPR-Cas9 in agriculture.

The other aspects listed, such as decreased nutritional value, weaker disease resistance, and reduction in yield, do not align with the objectives of CRISPR-Cas9 applications, which typically aim to improve, not diminish, the qualities of crops. Thus, the correct answer highlights a positive enhancement that CRISPR-Cas9 can bring to agricultural biotechnology.