A man has to plant exactly four varieties of flowers in a flower bed in his garden, one variety in each of the four rows, in an ascending order of height from the first row to the fourth row. The seven varieties available to the man, in ascending order of height, are red begonias (RB), pink petunias (PP), orange marigolds (OM), red geraniums (RG), white snapdragons (WS), yellow zinnias (YZ) and pink cosmos (PC). The following restrictions on color arrangements apply: No two varieties of the same color can be planted. Orange flowers cannot be planted in a row immediately adjacent to a row of yellow flowers. Which of the following is a color arrangement, from first row to fourth row, that the man can select for the flower bed?

Explanation: (E) The sequence must be in ascending order of height (from the varieties used) and adhere to the color restrictions. Available colors in height order: Red, Pink, Orange, Red, White, Yellow, Pink. (A) Pink, red, white, pink: Two Pinks - Invalid. (B) Pink, orange, white, red: Red (RG) is shorter than White (WS) but taller than Pink (PP). Not in ascending height order. Invalid. (C) Red, orange, yellow, pink: OM is next to YZ - Invalid. (D) Red, white, yellow, pink: Red (RG) is shorter than White (WS) and Yellow (YZ) is shorter than Pink (PC). Not in ascending height order. Invalid. (E) Red (RB), Pink (PP), Yellow (YZ), White (WS): Valid varieties in this color order: RB, PP, YZ, WS. Height order: RB < PP < YZ < WS. Colors: R, P, Y, W. No same colors. OM (Orange) is not adjacent to YZ (Yellow). Valid.