Apple founder Steve Jobs received patents on many of his ideas. While the patents existed, his ideas were

A) public goods and proprietary knowledge.
B) public goods but not proprietary knowledge.
C) private goods and proprietary knowledge.
D) private goods but not proprietary knowledge.

Steve Jobs' patented ideas were considered private goods because they were excludable and rivalrous, meaning only those who paid for them could use them, and their use by one person prevented simultaneous use by another. They were also proprietary knowledge because the patents gave Jobs and his company exclusive rights to use and profit from these ideas, preventing others from using them without permission.