. . . . . . . . and . . . . . . . . saves the publish and subscribe keys that we have generated with the PubNub Admin portal.

The correct answer is: A. public_key and subscribe_key

The PubNub Admin portal allows you to generate publish and subscribe keys. These keys are used to authenticate your application with the PubNub service. The publish key is used to publish messages to a PubNub channel, and the subscribe key is used to subscribe to a PubNub channel and receive messages.

The following code snippet shows how to save the publish and subscribe keys in a file:

“`
import json

with open(‘pubnub_keys.json’, ‘w’) as f:
json.dump({‘public_key’: pub_key, ‘subscribe_key’: sub_key}, f)
“`

The pubnub_keys.json file will contain the following JSON:

{
"public_key": "YOUR_PUBLISH_KEY",
"subscribe_key": "YOUR_SUBSCRIBE_KEY"
}

You can then use the keys in your application by loading them from the file.

The other options are incorrect because they do not represent the correct format for PubNub keys.