A substance through which light can pass completely is called a/an
A. Transparent body
B. Translucent body
C. Opaque body
D. None of these

Hint: Different materials passes different amount of light through depending on the composition of structure and hence are classified on different definitions
There are three categories:
1 transparent object
2 translucent objects
3 opaque objects

Complete step by step answer:
Transparent objects are the ones which allows almost all light falling on them to pass through them. Opaque objects are those which do not allow any light to pass through them.
Translucent objects lie in between of transparent and opaque objects.
Transparent and opaque are the extremes and translucent lies at the median. Considering the definition of all three categories of objects, we can see that the objects or substances which allow light falling on them to completely pass through are known as transparent objects. If we stand on the other side of such objects we can see that the light is visible from the other side unlike blurry in the case of a translucent object or even a faint shadow is formed in case of translucent objects or not visible in case of opaque objects.
Examples of such objects being glass surfaces, water and also air, cellophane paper.
So, the correct option of this question is A.

Note:
The above definition which helps us in categorizing different objects
Examples of opaque objects are wood, notebook, pillows.
These all objects find their uses in a variety of places.
Transparent object like glass is used to design spectacles, glass aquariums and even in household purposes.
Translucent objects like tissue are used in bathrooms for washing hands.
And opaque objects like wood are used in making decorative items, handles and doors.