Holly begins with 1 penny in her piggy bank. She adds 2 pennies on day 1, 4 pennies on day 2, and 8 pennies on day 3. She continues this pattern for 30 days.

Which statement describes why this sequence is a function?

Select each correct answer.


Each amount of pennies corresponds to a unique day in this sequence.

The graph of this sequence would pass the horizontal line test.

The graph of this sequence would pass the vertical line test.

Each day corresponds to a unique amount of pennies in this sequence.