Need !
holly begins with one penny in her piggy bank. she adds two pennies on day 1, four pennies on day 2, and eight pennies on day 3. she continues this pattern for 30 days.

which statement describes why this sequence is a function?

select each correct answer.
a the graph of this sequence would pass the horizontal line test.
b the graph of this sequence would pass the vertical line test.
c each day corresponds to a unique amount of pennies in this sequence.
d each amount of pennies corresponds to a unique day in this sequence.