Final answer:
The adjective clause in the given sentence is 'who were fond of their comforts,' which describes 'The Romans'. The correct option is (b) 'Were fond of their comforts', as this clause provides additional information about The Romans' penchant for comfort.
Step-by-step explanation:
When identifying an adjective clause, it's important to look for a group of words that contains a subject and a verb and works to modify or describe a noun in the sentence. In the example provided, the sentence is "The Romans, who were fond of their comforts, had indoor heating and plumbing." The adjective clause in this sentence is "who were fond of their comforts," which describes "The Romans" by providing more information about them.
Thus, among the given options, the correct answer is option (b) "Were fond of their comforts". This clause gives us more detail about 'The Romans' and why they may have had such amenities as indoor heating and plumbing. It underscores the notion that the Romans were not just advanced in engineering but also sought pleasure and comfort in their daily lives.
The Roman Society was known for its opulence and advanced infrastructure including features like aqueducts and plumbing systems, indicating their value for comfort, which is essentially what the adjective clause highlights.