Instruction: Determine the relevance between the query and the product title provided, and select your response from one of the available options.

Input:
Query: pool solar heater
Product: Immersion Heater | Submersible Water Heating with Full Stainless-Steel Guard and Thermostat| Heats 5 Gallons of Water in Minutes | Great for Small Bath Tub/Inflatable Swimming Pool U.S. Version

Options:
A: The product is relevant to the query, and satisfies all the query specifications.
B: The product is somewhat relevant. It fails to fulfill some aspects of the query but the product can be used as a functional substitute.
C: The product does not fulfill the query, but could be used in combination with a product exactly matching the query.
D: The product is irrelevant to the query.
Answer: B: The product is somewhat relevant. It fails to fulfill some aspects of the query but the product can be used as a functional substitute.