Question

the suez canal connected the mediterranean sea and
the caspian sea.
the red sea.
the atlantic ocean.
the persian gulf.

Explanation:

The Suez Canal is a man - made waterway. It is located in Egypt. Geographical knowledge about waterways and seas is relevant here. The Caspian Sea is an inland sea in Central Asia, far from the Suez Canal. The Atlantic Ocean is connected to the Mediterranean Sea through the Strait of Gibraltar. The Persian Gulf is in the Middle East, not directly connected by the Suez Canal. The Red Sea is connected to the Mediterranean Sea via the Suez Canal.

Answer:

the Red Sea.