Which of the following terms best describes this part of the selection?

In 12-tone composition, rows could be written __________

a) in spiral form b) in mirror form, or inverted c) to provide a strong sense of tonality d) based on Gregorian chant

"Maybe that person can't, um incorporate sickness into his sense of how things are supposed to go. Maybe vomit . . . and sores and disease . . . really frighten him, maybe. . . he isn't so good with death."

Fill in the blank(s) with the appropriate word(s).