A 27-year-old woman who resides in an area endemic to chloroquine-resistant Plasmodium falciparum malaria presents to the physician with fatigue, malaise, and episodes of fever with chills over the past 5 days. She mentions that she has episodes of shivering and chills on alternate days that last for about 2 hours, followed by high-grade fevers. Thereafter, she has profuse sweating and her body temperature returns to normal. She also reports that she is in her 7th week of pregnancy. Physical examination reveals the presence of mild splenomegaly. A peripheral blood smear confirms the diagnosis of P. falciparum infection. Which of the following is the most appropriate antimalarial treatment for the woman?