AWS documentation states that to connect to my DocumentDB Cluster, I need to use a query string that ends like so ?ssl_ca_certs=rds-combined-ca-bundle.pem&replicaS
?ssl_ca_certs=rds-combined-ca-bundle.pem&replicaS
Here are examples on how to programmatically connect to Amazon DocumentDB with C# (and other drivers) with both TLS enabled/disabled.
https://docs.aws.amazon.com/documentdb/latest/developerguide/connect.html