Find the area of the figure

The correct answer is: 19 sq. m

The figure consists of a verticle rectangle and a horizontal rectangle. 
At first, we will calculate the area of the verticle rectangle.
Length of verticle rectangle: 3 m
the breadth of the verticle rectangle: 5 m
Area of verticle rectangle = length     breadth
= 3  5
= 15 m²
Now we will find the area of a horizontal rectangle.
Length of horizontal rectangle: ( 7- 3 ) =  4 m
the breadth of the horizontal rectangle: 1 m
Area of horizontal rectangle = length     breadth
= 4  1
= 4 m²
The total area of figure = area of horizontal rectangle + area of verticle rectangle
= 15 + 4
=19 m²

So the correct option is a.