Which of the Following Would Be an Internal Attribution About

Which of the following would be an internal attribution about your behaviour or performance?

A) Your declining sales this quarter are due to worsening economic conditions.
B) The company's awkward information system makes it difficult to keep clients informed.
C) Your higher quality service this past year has been due largely to helpful coworkers.
D) You were unable to complete the product on time because the machinery kept jamming.
E) Your success this year is due mainly to your motivation to work hard.