Which of the following statements is true?

When the activity measure is the number of units sold, the revenue variance is favorable if the average actual selling price is greater than expected.

A favorable spending variance occurs when the actual cost is less than the amount of the cost in the static planning budget.

A revenue variance is favorable if the actual revenue is greater than the revenue in the static planning budget.

Multiple Choice

Only statement $1$ is true.

Only statement $2$ is true.

Only statement $3$ is true.

None of the statements are true.