Multiple choice general knowledge Fear of decaying matter Rhytiphobia Seplophobia Triskaidekaphobia Rectophobia Reveal answer Fill a bubble to check yourself B Correct answer Explanation Seplophobia is the fear of decaying matter or decomposing material. Rhytiphobia is fear of wrinkles, Triskaidekaphobia is fear of the number 13, and Rectophobia is fear of rectal diseases.