The correct option is B Febrile stage
Plasmodium infection causes an acute febrile illness, which is most notable for its periodic fever paroxysms occurring at either 48 or 72-hour intervals. The Plasmodium exhibit non-specific prodromal, symptoms a few days before the first febrile attack. These prodromal symptoms are generally 'flu-like'; and will be followed by febrile attacks, also known as malarial paroxysms.
So, the correct answer is option B.