Instruction: Given a query and a list of products denoted as A, B, C, ... with their titles, rank the products according to their relevance to the query. Output only a ranked list in which the most relevant product is at the top of the list.

Input:
Query: providing professional services as a business
Product list:
A: Data as a Service: A Framework for Providing Reusable Enterprise Data Services
B: Rude Dude: The Steve Rude Story
Answer: A,B