The right answer is tan(F). The triangle depicted is a right triangle due to the provided information. Additionally, it is indicated that the triangle is isosceles, making the sides adjacent to angles D and F equal. Both are 5 units long. The value of cos(F) is provided, as well as that for sin(F). Also, the sine value for angle D is noted. The tangent of F equals 1, differing from the given cos(F). Hence, the answer is the third option.
