Instruction: Rank the products A, B, C, ... based on their relevance to the provided query, and produce a ranked list with the most relevant product positioned at the top of the list.

Input:
Query: 300b tube amplifier
Product list:
A: Nobsound 6P1 6.8W x 2 Vacuum Tube Power Amplifier; Stereo Class A Single-Ended Audio Amp Handcrafted
B: Reisong A10 EL34 Hi-Fi Audio Stereo Tube Amplifier Single-end Class - A Amp
Answer: A,B