Answer
$3.0mm \leq D \leq 46mm$
Work Step by Step
Use the relationship on page 715 that defines the f-stop.
$$f-stop=\frac{f}{D}$$
$$D=\frac{f}{f-stop}$$
Calculate the high and low lens diaphragm diameters.
$$D_{1.4}=\frac{65mm}{1.4}=46mm$$
$$D_{22}=\frac{65mm}{22}=3.0mm$$
The range of diameters is $3.0mm \leq D \leq 46mm$.
