Correct Answer:
B. 1954, Manila
Pakistan signed the Southeast Asia Treaty Organization (SEATO) in 1954. This collective defense treaty was signed in Manila, the capital of the Philippines. SEATO was established to prevent communism from gaining ground in the region. Option B is correct, accurately stating both the year and the location of the signing. The other options are incorrect because while 1954 is the correct year, Karachi, Bangkok, and Jakarta were not the cities where the SEATO treaty was formally signed by the member nations.