Which of the following statements describes a characteristic of resin cements?

Resin cements are known for their excellent bonding capabilities and aesthetic qualities. Among the statements provided, the characteristic that accurately describes resin cements is that they tend to have an odor and can discolor restorations.

This is due to the nature of the materials used in resin cements, which can emit a scent, particularly during the curing process. Additionally, issues related to discoloration can arise if the cements are not correctly managed, especially when exposed to certain conditions or if they're not of high quality.

The other statements do not align with the properties of resin cements. They are not primarily temporary, as they are often used for both permanent and semi-permanent restorations based on the context in which they are applied. Resin cements are praised for their high retention strength and durability, contrary to the suggestion that they offer poor retention and strength. Lastly, resin cements are typically regarded as aesthetic options, often being used in situations where the appearance of the restoration is critical.