(a) That's right. There are two important things to notice about this example.
Firstly, the contract is for the purchase and sale of goods. Secondly, the seller is a person who deals in the type of goods sold (i.e. the sale takes place in the course of a business). This can be distinguished from occasional sales made by individuals who are not in the business of selling or dealing in such goods.
When both of these factors are present (as in the example) the sale of goods legislation in all Australian states and territories provides implied terms that specify what qualities the goods should have. What these qualtities are will be explained in the examples that follow.
If these two factors are not present, the principle 'caveat emptor' applies (let the buyer beware) and it is up to the buyer to check that the goods have the qualities required, or to include express terms in the contract requiring specific qualities.