Final answer:
The correct option is 4) painting. The Buffalo Union and similar Progressive Era single-sex clubs offered classes like cooking, sewing, and painting, but not dancing, as it was more common in mixed-gender social settings.
Step-by-step explanation:
The Buffalo Union, a representative of single-sex clubs during the Progressive Era, provided various opportunities for education and self-improvement. Typical offerings in such clubs included cooking, sewing, painting, and domestic skills to empower women within their traditional roles.
However, they did not typically include dancing, which was a popular form of entertainment and socializing found largely in mixed-gender settings like dance halls and was associated with the working class engaging in leisure activities after hours. This social activity was a stark contrast to the more reserved and structured environment of single-sex clubs like the Buffalo Union, which focused on domestic educational programs.