Answer: The correct option is 1.
Step-by-step explanation:
A polygon is said to be a heptagon if it has 7 vertices, 7 sides and 7 angles. A heptagon is called a convex heptagon if the line connecting the two vertices are lies completely inside the heptagon.
In the figures the black points shows the vertices.
Reason for correct option:
In figure 1 there are 7 angles, 7 sides and 7 vertices and the lines joining any two vertices are lies inside the figure, therefore it is an convex heptagon and option 1 is correct.
Reason for incorrect option:
In figure 2 and 3 the number of vertices and sides are 8, therefore the figure shows the octagon and option 2 and 3 are in correct.
In figure 4 the number of vertices and sides are 7 but there axis a line which connecting the two vertices and lies outside the figure as shown in below figure, therefore the option 4 is incorrect.