ans is A
Square brackets can surround a choice of single characters (i.e., one digit or one letter) you’d like to match. For example, [Cc]hapterwould match either Chapter or chapter, but [ch]apter would match either capter or hapter. Use a hyphen (-) to separate a range of consecutive characters. For example, chap[1-3] would match chap1,chap2, or chap3.
But if escape sequence(\) is used then it literally matches with that after \
so $rm chap0\[1-3\] will remove
Remove file chap0[1-3]