An advertiser enabled Conversion Optimizer and noticed a decrease in the number of conversions. What could have caused this decrase to occur?

An advertiser enabled Conversion Optimizer and noticed a decrease in the number of conversions. What could have caused this decrase to occur?

  A)  The cost-per-click (CPC) bid was lower than the recommended amount
  B)  The specific Conversion Optimizer code snippet was not added to the site
  C)  The maximum cost-per-acquisition (CPA) bid was lower than the recommended amount
  D)  The ads in the campaign are waiting to be approved