What'a the difference between "spacious" and "capacious" "source" and resource"? [closed]
If you look at the synonyms section of ODO you'll see that they are considered largely synonymous.
However, spacious ist he much more common word, which explains why it would show up as answer in your test.
If we have a look at the ten most common nouns that follow the two words we can see a pattern of use. Spacious is exclusively used for physical spaces, while capacious is also used in a more metaphorical sense being followed mostly by mind. There are several words which do not refer to great physical dimensions but, well the capacity to store something or take something in like the pockets or the stomach.
For the other two words I advise you to have a look at the dictionary as you did with the first two words.