Engagement Split is the Journey Builder activity that NTO should use. Engagement Split is an activity that allows you to split contacts based on how they interacted with a previous email send, such as opened, clicked, or converted. You can use this activity to include specific content for your most engaged customers and different content for your least engaged customers. Frequency Split is an activity that allows you to split contacts based on how often they have received messages from your account. Scoring Split is an activity that allows you to split contacts based on their Einstein Engagement Score.