What type of fabric is more likely to shrink when exposed to excessive moisture?

Cotton is more likely to shrink when exposed to excessive moisture due to its natural fiber structure. Cotton is a cellulose fiber that is highly absorbent and expands when wet. When it dries, especially under heat, the fibers can retract, leading to shrinkage. This characteristic is particularly pronounced in untreated or unpreshrunk cotton fabrics.

In contrast, synthetic fabrics, such as those made from nylon, are engineered to be more resistant to moisture and do not exhibit the same level of shrinkage. Silk, being a natural protein fiber, can also experience some shrinkage, but it is less common than with cotton. Therefore, cotton stands out as the fabric that is most susceptible to shrinkage when exposed to excessive moisture, making it the correct choice in this scenario.