You have a Python UDF in Snowflake designed to enrich customer data by calling an external API to retrieve additional information based on the customer ID. Due to API rate limits, you need to implement a mechanism to cache API responses within the UDF to avoid exceeding the limits. The UDF is defined as follows:

Which caching mechanism can be implemented MOST effectively WITHIN the Python UDF to minimize API calls while adhering to Snowflake's UDF limitations?
Correct Answer: A
Using 'functools.lru_cache' (Option A) is the most efficient and straightforward solution. It provides a built-in caching mechanism within the Python UDF's scope without requiring external dependencies or complex manual caching logic. Option B is not the best, as it will cause issues in multithreaded environment where this is not thread safe and could cause data inconsistency. Option C is related to Snowflake result cache which is independent of UDF cache needs and concerns. The temp table (option D) adds overhead by querying external tables within the UDF, making API execution slower rather than faster. And Option E needs external connections which increase infrastructure complexity.