Answer:
Option B is correct that is The cosine of an angle is a ratio.
Explanation:
In a triangle ,
Cosine of an angle is written as fraction of adjacent side by Hypotenuse side of right angled triangle.
or we can say that Cosine of an angle is written as fraction of Base side by Hypotenuse side of right angle triangle.
Fraction is also known as ratio.
Therefore, Option B is correct that is The cosine of an angle is a ratio.