A 9-year-old male with a history of fever and nonspecific symptoms presents with a bright red cheeks and a macular lacy rash over his body. Which of the following viruses is the most likely cause of this disease?

Parvovirus B19 (b) is the causative agent of erythema infectiosum (fifth disease). The infection occurs in two phases. First is the lytic, infectious phase characterized by nonspecific flulike symptoms (fever, chills, headache, and myalgia) that lasts about a week. This accompanied by a decrease in reticulocyte count and hemoglobin, which is not usually noticed in healthy children and adults. The second phase begins a week later when virus-specific IgG antibody appears and includes the characteristic "slapped cheek" appearance and lacy reticular rash. Adults often develop polyarthropathy or arthralgia. The rash and arthropathy are due to circulating antigen-antibody complexes. The rashes of rubella virus (c) and rubeola virus (measles virus) (d) occur in conjunction with fever. The lesions produced by HSV1 (a) and VZV (e) are vesicular in nature.