What’s a possible way to optimize toward a $10 cost per action (CPA) goal if your current CPA is $50? - The Future Of Ink

Home Bid Manager Optimization Assessment What’s a possible way to optimize toward a $10 cost per action (CPA) goal if your current CPA is $50?

Set a $10 goal, and bid very high.
Set a CPA goal of $60, and then incrementally increase the goal over time.
Set a $45 CPA, and then continue to lower it in $5 increments over time.
Set the counting method to include only a percentage of the post-view clicks.