To find the length of the rectangle, we can use the formula for the area of a rectangle, which is:
\[ \text{Area} = \text{Length} \times \text{Width} \]
Given that the area is 75 square centimeters and the width is 5 centimeters, we can plug in these values:
\[ 75 = \text{Length} \times 5 \]
To find the length, we divide both sides by 5:
\[ \text{Length} = \frac{75}{5} = 15 \text{ cm} \]
So the length of the rectangle is 15 cm.
The correct answer is:
B 15 cm