Answer:
The correct Answer is A).
Step-by-step explanation:
The design of the dome is based on the intersection of two circles. One horizontal and the other vertical.
The Pantheon which is was designed by the Harian Engineers took 4-5 years to build.
It was originally built as a temple to all the Roman gods back in the reign of Augustus, but destroyed in one of ancient Rome's many devastating fires. It was rebuilt around 120 CE, completed in the reign of Hadrian (who decided to confuse future archaeologists by re-using the original massive portico with its inscription crediting the building to Marcus Agrippa), and has remained remarkably intact for nearly 1900 years.
Cheers!