Which of the following statements are true about the decibel scale? (i) The decibel scale for sound intensity level is logarithmic and thus better related to how the human ear perceives loudness. (ii) The decibel scale is based on a ratio of a sound's intensity to a reference intensity. (iii) The decibel scale uses a reference intensity that is at the threshold for human hearing. Select the correct answer a. Only statements (i) and (ii) are true. b. Only statement (i) is true.c. Only statement (ii) and (iii) are true. d. Only statement (ii) is true. e. All three statements are true. f. Only statement (iii) is true.