A student is using a light microscope to study plant cell structures. They want to observe a chloroplast with an actual length of 5.0 μm5.0\ \mu\text{m}5.0 μm so that its image appears to have a length of 3.5 mm under the microscope. If the microscope is fitted with a 14× 14\times\,14× magnification eyepiece lens, which objective lens magnification must be selected to achieve this?
5×5\times5×
50×50\times50×
140×140\times140×
500×500\times500×