A marketer's Google app campaign seeks to increase app installs among all potential new users. The marketer does not have a clear target cost$-$per$-$install $($tCPI$)$ and does not want to set one. Which of the following bidding strategies should the marketer use?

a$.$

Max conversions

b$.$

None of these. All Google app campaign bidding strategies require the marketer to designate a tCPI.

c$.$

Target cost$-$per$-$action

d$.$

Target return$-$on$-$ad$-$spend