Answer:
d
Step-by-step explanation:
using the cosine ratio in the right triangle
cos B = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{BC}{AB}[/tex] = [tex]\frac{2}{10}[/tex] , then
B = [tex]cos^{-1}[/tex] ( [tex]\frac{2}{10}[/tex] ) ≈ 78.46° ( to 2 dec. places )