Part A
The central idea of the poem is:
2. The present location of the speaker is much less desirable than the seaside.
The speaker expresses a strong affection for the natural elements found by the seaside, contrasting those feelings with the lack of desire for their current location.
Part B
The first line of the poem helps develop the correct central idea from Part A by:
2. The line suggests that sometimes the true feelings of the speaker are hidden.
The speaker begins by indicating that there’s more to their love than mere words can convey, hinting that their true feelings revolve around the beauty of the seaside, which they find preferable to their current surroundings.