When the economy is at full employment, the Question 1 options:
natural unemployment rate equals the unemployment rate.
natural unemployment rate is equal to 10 percent.
frictional unemployment rate is equal to 0 percent.
unemployment rate is equal to 0 percent.
natural unemployment rate is equal to 0 percent.

natural unemployment rate equals the unemployment rate.

Explanation:

Full employment is a socio economic term that describes a situation in which the available labor resources are being used in the most efficient way possible ways.

In other words, it does not mean "zero unemployment", but rather it represents the hypothetical full employment level in which highest amount of skilled and unskilled labor can be employed within an economy at any period of time.