Correct Answer:
B. Ayub Khan
Explanation:
The second Constitution of Pakistan was promulgated on March 1, 1962, and officially enforced on June 8, 1962, by the military dictator Field Marshal Muhammad Ayub Khan, who was serving as President after declaring martial law in 1958.
### Important Facts:
- System of Government: Introduced a strong Presidential System, placing vast executive authority directly in the hands of the President.
- Electoral College: Established the 'Basic Democracies' system, where an electoral college of 80,000 members elected the President and Assemblies.
- Abrogation: Suspended and abrogated in 1969 by General Yahya Khan.