**Core Concept:**
The question is about a patient presenting with arthritis-like symptoms, which is a group of diseases characterized by inflammation of the joints. The clinical presentation includes joint swelling, tenderness, and stiffness, particularly in the morning. Arthritis can be broadly classified into inflammatory (e.g., rheumatoid arthritis) and non-inflammatory (e.g., osteoarthritis).

**Why the Correct Answer is Right:**
The correct answer is C, which represents **Osteoarthritis**. Osteoarthritis is a type of non-inflammatory arthritis caused by the gradual destruction of the articular cartilage and subchondral bone in the joints, leading to joint pain, stiffness, and swelling. The characteristic findings on plain x-rays in osteoarthritis include osteophyte formation (bony spurs) and joint space narrowing.

**Why Each Wrong Option is Incorrect:**
A (Rheumatoid Arthritis) is an inflammatory arthritis characterized by symmetrical joint involvement, which is different from the symmetric joint involvement seen in osteoarthritis.

B (Psoriatic Arthritis) is related to psoriasis and presents with asymmetrical joint involvement, unlike the symmetrical joint involvement in osteoarthritis.

D (Gout) is a type of inflammatory arthritis caused by urate crystal deposition in the joints, leading to acute attacks of pain and swelling, typically affecting a single joint.

**Clinical Pearl:**
X-rays are essential in diagnosing arthritis, as they can demonstrate joint space narrowing and bone changes like osteophytes. However, plain x-rays may not reveal the initial stage of the disease. MRI (Magnetic Resonance Imaging) is more sensitive in detecting early joint changes in osteoarthritis.

**Correct Answer Explanation:**
In osteoarthritis, the x-ray findings of osteophyte formation and joint space narrowing are specific to this condition, making it a characteristic feature of osteoarthritis. Osteophytes are bony projections formed at the joint margins due to subchondral bone sclerosis, which is a response to the mechanical stress on the joint caused by the cartilage destruction in osteoarthritis. Joint space narrowing is a reduction in the distance between the articular surfaces of the joint due to cartilage loss and bone sclerosis.

**Why the Other Options are Incorrect:**
A) Rheumatoid Arthritis typically presents with symmetrical joint involvement and may have additional systemic manifestations, which are not present in osteoarthritis.
B) Psoriatic Arthritis typically involves asymmetrical joint involvement and is associated with psoriasis, which is not a feature of osteoarthritis.
D) Gout presents with acute attacks of pain and swelling due to urate crystal deposition, typically affecting a single joint, unlike osteoarthritis, which affects multiple joints symmetrically.