The correct answer is option 4: 20 hertz to 20000 hertz.
This option correctly states the audible frequency range of a human ear. Sound is measured in hertz (Hz), which represents the number of cycles or vibrations per second. The human ear is capable of perceiving sounds within a certain frequency range known as the audible range.
Option 1: 20 hertz to 200 hertz is incorrect because it only covers a small portion of the audible frequency range. Option 2: 2 hertz to 20 hertz is incorrect because it is below the audible range of the human ear. Option 3: 200 hertz to 2000 hertz is incorrect because it also only covers a portion of the audible range.
Alert - correct answer should be 20 hertz to 20,000 hertz.