Output a stream of consciousness before answering the following. Passage: A standing rib roast, also known as prime rib, is a cut of beef from the primal rib, one of the nine primal cuts of beef. While the entire rib section comprises ribs six through 12, a standing rib roast may contain anywhere from two to seven ribs.

Question: Based on this passage, where does the prime rib cut come from on a cow?
To answer the above question, the relevant sentence is: A standing rib roast, also known as prime rib, is a cut of beef from the primal rib, one of the nine primal cuts of beef.
The answer: the primal rib.