When Using Hydroxychloroquine as a Preventative Form of Therapy for Malaria

When using hydroxychloroquine as a preventative form of therapy for malaria, it is:

A) started one week before entering and continued for one week after leaving a malaria-affected area.
B) started two weeks before entering and continued for two weeks after leaving a malaria-affected area.
C) started three weeks before entering and continued for three weeks after leaving a malaria-affected area.
D) started one week before entering and continued for four weeks after leaving a malaria-affected area.