In the context of 1 Corinthians 7, what is Paul's primary concern regarding marriage and singleness, and how does this relate to his eschatological perspective?

A Paul advocates for mandatory celibacy to avoid worldly distractions and prepare for the imminent return of Christ. B Paul establishes a rigid hierarchy within marriage, emphasizing the husband's authority and the wife's submission as essential for spiritual growth. C Paul prioritizes individual freedom and self-fulfillment, encouraging believers to choose whichever state (married or single) best suits their personal desires. D Paul emphasizes that both marriage and singleness are valid callings, each with its own challenges and opportunities for serving God, given the urgency of the present age and the believer's focus on the Lord.