The correct answer is B: Implement RDS Proxy to efficiently manage connections in high-access environments. RDS Proxy is designed to handle a large number of database connections by pooling and reusing connections, which reduces the overhead of establishing new connections and helps mitigate the 'too many connections' error. Options A, C, and D involve either changing database settings or managing Lambda concurrency, but they do not directly address the root cause of connection saturation as effectively as using RDS Proxy.