A is the only answer that would prove that security is needed on them
Prepositions indicate direction, time, location, and spatial relationships, as well as other abstract types of relationships.
Prepositions indicate relationships between other words in a sentence.
Many prepositions tell you where something is or when something happened.
As the name suggests they generally tell position if something. Like, behind, front, on, at etc.
Explanation:
Meter is the basic rhythmic structure of a line within a work of poetry.
