After THR surgery by 9 days the patient suffered from severe pain in the thigh and calf muscle ,redness and fever and diffuse edeama in the leg but with normal walking the diagnosis is

After THR surgery by 9 days the patient suffered from severe pain in the thigh and calf muscle ,redness and fever and diffuse edeama in the leg but with normal walking the diagnosis is?

a. infection

b. DVT

c. dislocation  of the joint

d. cellulitis