Economic-Leah Math question-thank you?

Question

At a price of $15, Marta buys 3 CD's per month. When the price increases to $20, Marta buys 2 CD's per month. Leah says that Marta's demand for CD's has decreased. Is Leah correct?

Yes, Leah is correct.

No, Leah is incorrect. Marta's demand has increased.

No, Leah is incorrect. Marta's quantity demanded has decreased, but her demand has stayed the same.

No, Leah is incorrect. Marta's quantity demanded has increased, but her demand has stayed the same.

No, Leah is incorrect. Marta's quantity demanded has decreased and her demand has increased.

Answer 1

d) No, Leah is incorrect. Marta's quantity demanded has increased, but her demand has stayed the same.