Pakistan signed a frontier agreement with Iran in:

This question requires knowledge of a specific historical event in Pakistan's international relations. Frontier agreements are significant diplomatic milestones that define national boundaries and foster regional stability.

• Option B: "1958" is the correct answer. Pakistan and Iran signed a crucial frontier agreement in 1958, which helped delineate their shared border and resolve long-standing territorial issues. This agreement was a significant step in strengthening bilateral relations between the two neighboring countries.
• Option A: "1947" was the year of Pakistan's independence, not the signing of this specific frontier agreement.
• Option C: "1967" is incorrect; no major frontier agreement with Iran was signed by Pakistan in this year.
• Option D: "1977" is also incorrect; this year does not correspond to the signing of the frontier agreement in question.