a. Now that you have the test results, you need to select one to invest in. Please explain which one you choose and why.
able[[CPI,0.12,0.08,0.18,0.12],[D1 Retention Rate,24%,10%,28%,22%
CPI D7 Retention Rate D1 Retention Rate one you choose and why. 12% 24% 0.12
5% 10% 0.08
14% 28% 0.18
12% 22% 0.12