What is the White House Press Briefing Room built on top of?

Here is the question :

WHAT IS THE WHITE HOUSE PRESS BRIEFING ROOM BUILT ON TOP OF?

Here is the option for the question :

• A graveyard
• A missile silo
• A swimming pool
• A chapel

The Answer:

And, the answer for the the question is :

Explanation:

[STC0016313]. In 1933, President Franklin D. Roosevelt spearheaded a fund-raising effort to pay for the construction of a swimming pool in the White House. Prior to this, he had sought treatment for his polio by swimming in therapy pools. It was created in place of the previous janitorial quarters that were located between the White House and the West Wing. Nearly 40 years later, when the White House decided it needed its own press room, President Nixon made arrangements for it to be constructed on top of the former swimming pool.