The correct answer is: A. than
The word “than” is used to compare two things. In this case, the two things being compared are donating money and distributing clothes. The sentence is saying that many people prefer donating money rather than distributing clothes.
The word “but” is used to contrast two things. In this case, the sentence would be saying that many people prefer donating money but they also distribute clothes.
The word “to” is used to indicate a destination. In this case, the sentence would be saying that many people prefer donating money to charities that distribute clothes.
The word “without” is used to indicate the absence of something. In this case, the sentence would be saying that many people prefer donating money without having to distribute clothes themselves.
I hope this explanation is helpful! Let me know if you have any other questions.