The correct answer is A. She said that she had to have a computer to prepare a powerpoint presentation.
The word “must” is used to express a strong obligation or necessity. In this case, the speaker is saying that she has no choice but to have a computer in order to prepare a PowerPoint presentation.
The other options are not as strong as “must.” Option B, “should,” is used to express a recommendation or suggestion. Option C, “would,” is used to express a possibility or intention. Option D, “could,” is used to express ability or permission.
In this case, the speaker is not simply recommending or suggesting that she have a computer. She is stating that she has no choice but to have one.