The correct answer to this open question is the following.
Although there are no options attached, we can say that the major factor in spurring on Iran's development of nuclear weapons in the 1980s was the victory of the Revolutionary forces in Iran, that overthrew the Shah, the last one that ruled over Iran. So in 1981, after the civil war ended, Iran authorities decided to continue the development of nuclear weapons as a way to defend the sovereignty of the country. In that time, the Soviet Union decided to support Iran sending expert scientists to help Iran to develop its own research program.
The ancient Roman republic had three branches of government. In the beginning, the legislative branch was the Senate, a group made up of 300 citizens from Rome's patrician class, the oldest and wealthiest families of Rome. It was the patricians, tired of obeying the king, who revolted and threw out Tarquinius Superbus.
Darius the great conceptualize his empire by emphasizing the system of Taxation to gain more financial wealth for the kingdom.
He expect all the tax collector should be very honest and should not accept bribery
hope this helps
