Problem: A 34-year-old woman presents to the clinic for routine sexually transmitted infection (STI) screening. She is asymptomatic and reports having 5 cisgender male sex partners during the past 3 years. Laboratory tests show a positive treponemal enzyme immunoassay (EIA) and a positive Rapid Plasma Reagin (RPR) at a titer of 1:64. Tests for HIV and other STIs are negative. Her last screening for STIs (including syphilis) was about 3 years ago. She has no history of syphilis or other bacterial STIs. A diagnosis of late latent syphilis is made, and she is treated with three doses of intramuscular benzathine penicillin G 2.4 million units, administered at 1-week intervals (total dose of 7.2 million units). For this woman, what is the acceptable time frame to expect the nontreponemal serologic tests to decline appropriately (fourfold) without being concerned for treatment failure? Within 2 months Within 6 months Within 12 months Within 24 months