Question

the us recession in the 1970s was caused by
an oil embargo.
energy interdependence.
low unemployment.
president nixons resignation.

Explanation:

The 1973 oil embargo by OPEC led to a sharp rise in oil prices, which triggered high inflation, supply chain disruptions, and economic contraction in the US, causing the 1970s recession. Energy interdependence is a broader condition, not a direct cause; low unemployment is the opposite of a recessionary trait; Nixon's resignation did not drive the recession.

Answer:

an oil embargo.