A 35 year old factory worker presents for eval of pain in his left arm. He denies any acute trauma or injury. His job involves inspecting jars and he has to test the opening and closing of the jar lids. He denies fever or chills. On exam there is no swelling over the elbow. You palpate the olecranon process, and he has tenderness on the left lateral epicondyle but not on the medial epicondyle. What is your most likely diagnosis?

a) olecranon bursitis
b) osteoarthritis
c) lateral epicondrylitis
d) epicondylar fracture