Find the synonym of the underlined word.
That big house surrounded with great trees had served as a hospital during the war.
(a)functioned
(b)exerted
(c)moaned
(d)reconciled
(e)placated

Hint: Try to understand the meaning of the word, as accurately as possible, by understanding the sentence. Then, go through the options one by one and choose the word similar in meaning to the given word, i.e. a synonym.

Complete answer: A synonym is a word or a phrase that has the same or nearly the same meaning as another word or phrase in the same language, for example, ‘near’ is a synonym of ‘close’, as they have the same meaning as each other, so they can replace each other in any given sentence. The word ‘served’ refers to ‘be of some specified use'. This word is usually used as a verb. Another synonym of this word can be ‘performed’.
Now, we know the meaning and usage of the given word. Let’s look at the given options:
(a)functioned - The word ‘functioned’ refers to ‘fulfil the purpose or task of (a specified thing)'. This word has the exact meaning as the given word. It is the synonym of the given word ‘served’. This is the required answer. So, this is the correct option.
(b)exerted - The word ‘exerted’ refers to ‘apply or bring to bear (a force, influence, or quality)’, so this word has a different meaning to the given word. It cannot be the synonym of the given word ‘served’. This is not the required answer. So, this is an incorrect option.
(c)moaned - The word ‘moaned’ refers to ‘make a long, low sound expressing physical or mental suffering or pleasure’, so this word has a different meaning to the given word. It cannot be the synonym of the given word ‘served’. This is not the required answer. So, this is an incorrect option.
(d)reconciled - The word ‘reconciled’ refers to ‘restore friendly relations between’, so this word has a different meaning to the given word. It cannot be the synonym of the given word ‘served’. This is not the required answer. So, this is an incorrect option.
(e)placated - The word ‘placated’ refers to ‘make (someone) less angry or hostile’, so this word has a different meaning to the given word. It cannot be the synonym of the given word ‘served’. This is not the required answer. So, this is an incorrect option.

Note: If you are aware of the meaning of the given word, you can go through the option and use the elimination method to eliminate the undesired options and choose the correct answer.