Option A: Direct variation ;

Step-by-step explanation:
From the graph, some of the points that the line passes through are
,
and

Thus, direct variation is the relationship between two variable in which one is the constant multiple of the other.
The expression can be written as

Substituting the coordinate
in
, we get,

Also, substituting the coordinate
, we get

Thus,
which is direct variation.
Hence, Option A is the correct answer.