Answer:
B. 140 square feet
Explanation:
The area of the floor is 119.9 square feet.
Mandana wants to order between 15% and 20% extra of the materials.
15% of 119.9 =

=
square feet rounding to 138 sq feet.
20% of 119.9 =

=
square feet rounding to 144 sq feet.
We can see that 140 sq feet lies between these two values.
So, the answer is 140 square feet.