Final answer:
Bob's right to seek substitute goods due to the seller's failure to deliver is known as the right to 'cover' under the Uniform Commercial Code.
Step-by-step explanation:
Bob's right to obtain substitute goods for those that were due under the contract is the right to obtain. In contract law, specifically under the Uniform Commercial Code (UCC), which governs the sale of goods in the United States, cover refers to the buyer's ability to purchase substitute goods when the seller fails to deliver what was promised in a contract. It is a remedy that allows the buyer to mitigate damages by purchasing the goods from another source, possibly at a different price. The buyer can then seek to recover any additional costs incurred from the seller who breached the original contract.