If an annulus has an inner diameter of d 1 and an outer diameter of d 2 then the equivalent diameter is

If an annulus has an inner diameter of d 1 and an outer diameter of d

1.	If an annulus has an inner diameter of d₁ and an outer diameter of d₂ then the equivalent diameter is
A.	2 d<sub> 2 </sub> d<sub> 1</sub>
B.	d<sub> 2 </sub> 2 d<sub> 1</sub>
C.	d<sub> 1 </sub> d<sub> 2 </sub>
D.	d<sub> 2 </sub> d<sub> 1</sub>
Answer» E.