Sailed - is that a proper or a common noun

Common Noun!

Explanation: This is easy. A proper noun is something specific.

A common noun is not specific.

Example:

Common Noun Version: restaurant

Proper Noun Version: Burger King

hello,

your answer is a) the metaphor suggests that the poetic themes are serious and dark.

collins is comparing the poem to a dark room. he is suggesting that the poems theme is serious and wants you to understand it. you don't need to understand the poet in order to understand the poem. you also don't need to move around while reading it. he is simply saying the poem has a dark and serious theme.

- i.a -