after THR surgery by 5 days the patient suffered from sever pain in the thigh and calf ms ,redness and fever and diffuse edeama in the leg but with normal walking the diagnosis

after THR surgery by 5 days the patient suffered from sever pain in the thigh and calf ms ,redness and fever and diffuse edeama in the leg but with normal walking the diagnosis is?
a. infection
b. DVT
c. dis of the joint
(b)