The correct answer is: 
 [C]: "
 37, 680 mm³ " .
________________________________________________________
Step-by-step explanation:
________________________________________________________
The formula for the volume, "
V" , o
f a cylinder is: → V = 
 * r² * h
 * r² * h ; 
 → in which "
r = length of radius" ; "
h = height" ; 
________________________________________________________ {Note that the formula for the 
volume, "
V" , 
of a cylinder is:  → " 
Base area * height " .
________________________________________________________ → Specifically, for a cylinder, the "Base area" is the area of a "circle", because the base is a circle; 
 → and the formula for the "
area of a circle = [
tex] \pi [/tex] * r² " ;
 → in which "
r = 
length of the radius" . 
As such, t
he formula for the volume, "
V" 
, of a cylinder is:______________________________________________________  → Volume = (Base area) * (height) ; 
 = ( 
 r² ) * h
 r² ) * h  ;
______________________________________________________
 → V = 
 r² h
 r² h ; 
 in which: "
V = volume {in "
cubic units" ; or, write as "
 units³ "
 } ;
 "
r = radius length" ; 
 "
h = height" ;
_____________________________________________________ → Now, 
we shall solve for the volume, "
V", of the given cylinder in this question/problem:
_____________________________________________________ → V = 
 r²
 r² h ; 
 in which: "
r = radius = ? " ; 
 → To find "
r" ; We are given the diameter, "d = 40 mm" ;   
→ Note that: 
"r = d/2 = (40 mm) / 2 = 20 mm " ; 
 {i.e., "the radius is half of the diameter".}.  
→ "
 r = 20 mm " ;  
→ " 
h = height = 30 mm " {given in figure) ;  
 → For
 
 
 ; let us use " 
3.14 " — which is a commonly used approximation. 
 → For this question/problem, none of the answer choices are given "
in terms of 

 " ; 
 → so we shall use this 
"numerical value" as an "
approximation" ; 
_______________________________________________________Now, let us plug in our known values into the formula;
 and calculate 
to find the volume, "
V", 
of our given cylinder; 
as follows:_______________________________________________________
  → V = 
 r² h
 r² h  ;  
= (3.14) * (20 mm)² * (30 mm) ;  
 = (3.14) * (20)² * (mm)² * (30 mm) ;  
= (3.14) * (20)² * (30) * (mm³) ;  
= (3.14) * (400) * (30) * (mm³) ;  
=  37, 680 mm³
__________________________________________________
The volume is: " 
37, 680 mm³ " ; 
 → which is: 
Answer choice [C]:  " 
37, 680 mm³ " .
___________________________________________________
Hope this answer and explanation—albeit lengthy—is of some help to you.
Best wishes!