Correct Answer:
A. Tarbela Dam
The correct answer is Tarbela Dam. Located on the Indus River in the Khyber Pakhtunkhwa province, Tarbela Dam is Pakistan's largest and most significant dam in terms of both size and power generation[reference:0][reference:1].
Why Tarbela Dam Is the Largest
Tarbela Dam is the world's largest earth-and-rock-fill dam by structural volume and the biggest electricity generation facility in Pakistan[reference:2][reference:3][reference:4]. Its key features are:
- Size: The dam is 143 meters (470 feet) high and 2,743 meters (9,000 feet) long[reference:5].
- Storage: It has a total storage capacity of 13.7 billion cubic meters, making it the largest reservoir in the country[reference:6].
- Power: It has an installed power generation capacity of 4,888 MW, providing over half (51.6%) of WAPDA's total hydropower capacity[reference:7][reference:8].
Why the Other Options Are Incorrect
- Mangla Dam (Option 2): While Mangla is the "biggest reservoir in terms of water storage" (with 7.277 MAF), it is smaller than Tarbela in structural volume, power generation capacity, and overall size[reference:9][reference:10][reference:11].
- Warsak Dam (Option 3): Warsak Dam is a much smaller concrete gravity dam on the Kabul River with a height of 76.2 meters and an installed capacity of only 243 MW[reference:12][reference:13][reference:14].
- None of these (Option 4): As Tarbela Dam is unequivocally the largest, this option is incorrect.
Therefore, Tarbela Dam is the only correct answer, as it is Pakistan's largest dam by every significant measure.