This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Woman of 30-years with Raynaud's phenomenon, polyahritis, dysphagia of 5-years and mild Sclerodactyl, blood showing Anti-centromere antibody positive, the likely cause is 
Select and explain. 
A. CREST, B. Mixed connective tissue disorder, C. SLE, D. Rheumatoid ahritis
A: CREST
Answer: A: CREST 
Explanation: Ans. is 'a' i.e., CREST