Evening By Victoria Mary Sack-ville-West
When little lights in little ports come out, Quivering down through water with the stars, And all the fishing fleet of slender spars, Range at their moorings, veer with tide about; When race of wind is stilled and sails are furled, And underneath our single riding-light, The curve of black-ribbed deck gleams palely white, And slumbrous waters pool a slumbrous world; Then, and then only, have I thought how sweet, Old age might sink upon a windy youth, Quiet beneath the riding-light of truth, Weathered through storms, and gracious in retreat. How do the lines in bold develop the theme of the poem?
A. They create tension between action and inaction.
B. They imply the growing darkness of death.
C. They suggest the end of an active life.
D. They support the metaphor of sailing.

Theme is described as the dominant idea of any literary work that functions to advance the plot and carry the narrative forward. It reflects the meaning of the work as a whole and also described as the unifying element that binds all the elements of the plot in a single thread.

In the given question, the lines in bold contribute to develop the theme of the poem as the use of specified words imply 'the end of an active life'('Evening' the title itself suggests the end of day or activeness) and leading to a passiveness which is the central unifying idea of the poem that the author intends to convey. These lines unifies the poem together with one single idea. Thus, option C is the correct answer.