Answer: the second option is the correct answer.
Step-by-step explanation:
Triangle ABC is a right angle triangle.
From the given right angle triangle,
AB represents the hypotenuse of the right angle triangle.
With m∠B as the reference angle,
BC represents the adjacent side of the right angle triangle.
AC represents the opposite side of the right angle triangle.
To determine Sine m∠B, we would apply
the Sine trigonometric ratio.
Sin θ = opposite side/hypotenuse. Therefore,
Sin B = √7/2√7
Sin B = 2