Option C (4.99 units).
Step-by-step explanation:
The triangle ABD is a right angled triangle, in which the perpendicular (AB) is given by 3 units and the angle opposite the perpendicular is given by 31 degrees. The question requires to find the length of the line segment BD. In the triangle ABD, the line BD acts as a base of the triangle. Given that AB = 3 units, and base is unknown, the following formula will be used:
tan ฮธ = Perpendicular/Base.
Plugging in the values:
tan 31 = 3/BD,
BD = 3/tan 31.
BD = 4.99 units (to the nearest hundredth).
Therefore, Option C is the correct answer!!!