Marrisa added 1.56 and 13.47. She got 29.07. What mistake could Marrisa have made?

She forgot to move the decimal point to the left after she added.
She lined up the front numbers instead of the decimal places.
She lined up the last numbers instead of the decimal places.
She didn’t carry correctly between place values.

The mistake Marrisa made is that she didn't line up the decimal places when adding 1.56 and 13.47.