Answer:
Correct answer is upper right rectangle (with 3rd strip shaded)
Explanation:
Observe the pattern carefully. This pattern consists of 5 rectangles. Each rectangle is divided into 4 vertical strips.
The 1st rectangle has one shaded strip - the 4th strip, the 2nd rectangle has shaded strip - the 3th strip, the 3rd rectangle has one shaded strip - the 2nd strip, the 4th rectangle has shaded the 1st strip
and so on
the 5th rectangle has shaded the 4th strip, the 6th rectangle has shaded the 3rd strip, ...
Thus, correct answer is upper right rectangle (with 3rd strip shaded)