If a performance standard is found to be stable or consistent over time, it is said to be: a. relevant. b. free from contamination. c. valid. d. reliable.

Reliable.

Explanation:

Reliability is a term used in statistics and psychometric evaluations. These refer to the stability or consistency of the data obtained in an investigation.

For an investigation to be considered valid, it must be consistent over time, and under similar circumstances. Otherwise, it is considered that the research is not valid enough to accept the results obtained as accurate.

I hope this information can help you.

not  

cuba  

russia  

iraq  

el salvador  

explanation:

known as the land of volcanoes, el salvador has visit seismic tremors and volcanic movement. it is the main nation in central america that does not have a coastline on the caribbean sea. about portion of all salvadorans live in the wide open. they are poor and don't have power or running water in their homes. in 1525, pedro de alvarado, a lieutenant of cortés's, vanquished el salvador. el salvador, with alternate nations of central america, pronounced its freedom from spain on sept. 15, 1821, and was a piece of a league of central american states until the point when that association broke up in 1838.