Final answer:
Option C is the best description, where the first quatrain of Sonnet 75 depicts the speaker's effort to immortalize his love, and the second quatrain shows the beloved's opposition to the notion.
Step-by-step explanation:
The relationship between the first and second quatrains in Edmund Spenser's Sonnet 75 is best described by option C: The first shows the speaker's actions; the second shows the beloved's opposition to them. In this sonnet, the speaker attempts to immortalize his love by writing his beloved's name on the sand, only for the waves to wash it away. The beloved points out the futility of this action in the second quatrain, highlighting the transient nature of life and love, and suggesting that such feats are impossible.