Choose two answers. A zero dollar sale is showing up in your statistics. It means that:

…one of your customers purchased, then cancelled their purchase of an SEMrush account.
…one of your clients activated a free seven day trial.
…one of your customers purchased a non-standard payment plan.

The correct answer is:

…one of your customers purchased, then cancelled their purchase of an SEMrush account.
…one of your clients activated a free seven day trial.