Concept:The first computing machine is the earliest known device created to help people perform calculations.Explanation:The Abacus was invented between 2700 and 2300 BC.It is considered the first computing machine known to mankind.The other options were developed much later in history.Napier bones and the slide rule came after the Abacus, and the Pascal calculator was built in the 1600s.Therefore, the earliest computing machine is the Abacus.Answer:D. Abacus