Answer:
Options (1), (2), (3)
Explanation:
Let the equation of the line is,
y = mx + b
Here m = slope of the line
b = y-intercept
Given line on the graph is passing through two points (-3, 0) and (0, 1).
Slope of this line will be,
m =

=

=

y-intercept of the line 'b' = 1
Equation of the line will be,
y =

If the points given in the options satisfy the equation, they will be the solution of the line.
Option (1),
For (3, 2),
2 =

2 = 2
True.
(3, 2) is the solution.
Option (2)
For (21, 8),
8 =

8 = 8
True.
(21, 8) is the solution.
Option(3)
For (-15, -4),
-4 =

-4 = -4
True.
(-15, -4) is the solution.
Option (4)
For (12, 9)
9 =

9 = 5
False
(12, 9) is not the solution.
Option (5)
For (-6, 1)
1 =

1 = -1
False
(-6, 1) is not the solution.
Therefore, Options (1), (2), (3) are the solutions.