Instruction: Evaluate the relevance between the query and product title, and choose the most accurate option from the given options.

Input:
Query: #10 window envelopes not self seal
Product: 500 No. 9 Double Window Security Envelopes - Designed for Quickbooks Invoices and Business Statements with Self Seal Peel and Seal Flap - Number 9 Size 3 7/8 Inch X 8 7/8 Inch

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.