PT 20 S3 Q15

A jeweler makes a single strand of beads by threading onto a string in ... ...

If on an eightbead strand the second, third, and fourth beads from the clasp are red, green, and yellow, respectively, and the sixth and seventh beads are purple and red, respectively, then which one of the following must be true?
(A) The first bead is purple.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Sequencing: Lesson Set 5 (of 5) - Repetition/Omission