(c) That's right. This question involves the contents of a contract, and terms implied by legislation into contracts for the sale of goods. You need to recall when the relevant sale of goods legislation makes it an implied term of a contract either that the goods must be suitable for the buyer's purpose; or that the goods are of merchantable quality, or both.
It becomes an implied condition of a contract for the sale of goods that the goods must be of merchantable quality when the goods are bought by description, from a seller who deals in goods of that description. Relevant cases are: Australian Knitting Mills v Grant; and David Jones v Willis. On the given facts, both of these requirements are met. The goods are described as 'bottling jars' and the seller is the manufacturer. Accordingly, it becomes a term of this contract that the jars are of merchantable quality. It should be noted that Astrid has not examined the jars in any way that would have revealed any defect.
It becomes an implied condition in a contract for the sale of goods that the goods will be suitable for the buyer's purpose when: the sale is by description; the seller deals in goods of that description; the buyer has informed the seller of the purpose for which the goods are required, and the buyer indicated reliance on the seller to supply suitable goods. The relevant case is Expo Aluminium v Pateman.
The first two of these requirements are met because the goods are described as 'bottling jars' and the seller is the manufacturer of them. However there are no facts in the case study on which to satisfy the last two elements. Astrid has only asked for standard bottling jars, and has not indicated that they must be heat resistant, or suitable for bottling hot jam. Accordingly, it would not become a term of the contract that the jars were suitable for Astrid's purpose of bottling jam.