A nurse is teaching a prenatal class about infection prevention at a community center. Which of the following statements by a client indicates an understanding of the teaching?

Varicella (chickenpox) is contagious until all lesions have crusted over — once crusted (typically 5–7 days after onset), the client is no longer infectious. Visiting after this stage is safe. Handwashing should be done for at least 20 seconds (not 10). Antibiotics treat bacterial infections, not viruses — misuse contributes to antibiotic resistance. Pregnant women should never clean cat litter boxes due to the risk of Toxoplasma gondii infection, which can cause severe fetal damage.