Answer:
The correct answer is: They worshipped one God, not many gods
Step-by-step explanation:
According to the historical records of the Bible and the Torah the ancient israelites constitute the initial monotheistic group, which is a descendant of the post-Flood patriarchs Abraham, Isaac and Jacob. It is often quoted in this books by the phrase 'the god of Abraham, the God of Isaac, and the God of Jacob...' reinforcing that they worshipped just one God, the same God.
They believe in a single good and just God, but also extremely jealous and demanding in regard to the faithfulness that the people owe them by virtue of the covenant sealed with Abraham and his descendants.