Using various attribution models in the Model Comparison Tool, a campaign manager noticessomething that makes her increase her investment in Google Display ads. What might she haveseen?

A certain channel received a small share of her investment and drove a
proportionally low conversion volume.
A channel received none of her investment.
A certain channel received a bulk of her investment and proportionally drove a high
conversion volume.
A certain channel received a bulk of her investment and disproportionally drove a low conversion volume