Sonja multiplied 623 x 47 using the standard algorithm. her teacher asked her to check her work, because she did not correctly follow the steps. based on her work shown in the image, what reasonable conclusion can be drawn?

a) when carrying numbers into the next columns, she reversed the digits.

b) she multiplied straight down the columns, like she would if she were adding.

c) she forgot to add the value of the carried digits after multiplying each row.

d) before beginning to multiply by the tens digit, she forgot to use a place holder.