Final answer:
Physical readiness assessments for service members are conducted twice a year with a minimum interval of 4 months between them.
Step-by-step explanation:
Service members are assessed for physical readiness at least twice a year with a minimum time of 4 months between Physical Fitness Assessments (PFAs). This requirement ensures that service members maintain physical readiness while also providing adequate recovery time between assessments. Therefore, the correct answer to the question is B) 4 months.