Final answer:
To randomly split leads into four cohorts in Marketo, use the 'Single Flow action: Add to List with add choice and Random Sample'. This utilizes a flow step in a Smart Campaign to distribute leads into lists using a 'Random Sample' condition.
Step-by-step explanation:
If you want to split up a group of leads into four randomly selected cohorts and put each group into its own static list, the correct option to achieve this in Marketo would be D) Single Flow action: Add to List with add choice and Random Sample. This action will allow you to segment your leads into separate lists by using a flow to add leads to a list and utilizing a random sample choice to distribute them evenly and randomly. Options involving 'random' type programs or imports might sound feasible, but they do not offer the precision or the functionality required for the task described.
For instance, when creating a Smart Campaign, you would use a flow step with the 'Add to List', and then set choices to distribute the leads randomly. You can use a 'Random Sample' condition to ensure that each lead has an equal chance to be placed into any of the four lists. By setting the random sample percentage to 25% for each list, each cohort will be randomly populated, mirroring methods similar to drawing random numbers or selecting test subjects at random.