Answer:
The dimensions of this rectangle are 65 in by 39 in ⇒ B
Step-by-step explanation:
Let us use the ratio method to solve the question
∵ The perimeter of the rectangle = 2(length + width)
∵ The perimeter of a rectangle is 208 inches
∴ 208 = 2(length + width)
→ Divide both sides by 2
∴ 104 = length + width
∵ The ratio  of its length to its width is 5: 3
∴ The sum of the ratios = 5 + 3 = 8
→ By using the ratio method
→  length  :  width  :  length + width
→  5      :  3     :  8
→  x       :  y     :  104
→ By using cross multiplication
∵ x × 8 = 5 × 104
∴ 8x = 520
→ Divide both sides by 8
∴ x = 65
∵ y × 8 = 3 × 104
∴ 8y = 312
→ Divide both sides by 8
∴ y = 39
∵ x and y represents the length and the width of the rectangle
∴ The length = 65 inches
∴ The width = 39 inches
∴ The dimensions of this rectangle are 65 in by 39 in