Semicircle perimeter = curved arc + diameter.<br><br>Curved arc = \(\frac{1}{2} \times 2\pi r = \pi r\).<br><br>Radius = \(2z\) cm, so:<br>&bull; Curved arc = \(\pi \times 2z = 2\pi z\) cm<br>&bull; Diameter = \(2 \times 2z = 4z\) cm<br>&bull; Perimeter = \(2\pi z + 4z\) cm<br><br>Final Answer: B: \((2\pi z + 4z) \text{ cm}\)