Final answer:
The perm product with the least strong odor compared to others is the Acid perm, due to its lower pH and the use of glyceryl monothioglycolate which emits a milder scent.
Step-by-step explanation:
The perm product that does not smell as strong as other perm products is B) Acid perm. Acid perms are milder and have a significantly lower pH than alkaline perms. Because of their gentler nature, they tend to have a less pungent odor. Unlike alkaline perm solutions or ammonium thioglycolate perms that have a stronger smell due to higher alkalinity, acid perms use glyceryl monothioglycolate as the active ingredient, which does not emit as strong of an odor. Exothermic perms, on the other hand, produce heat through a chemical reaction, and this process doesn't necessarily equate to a milder scent. The choice between these perms often depends on the hair type and desired result, with acid perms being better suited for delicate or damaged hair.