Final answer:
The length of arc BC can be calculated using the formula arc length = radius × angle; with a radius of 2.5 cm and an angle of 4 radians, the arc length is 10 cm.
Step-by-step explanation:
The length of arc BC on a circle can be calculated using the formula for the arc length, which is the angle in radians (A) multiplied by the radius (r). In this question, we are given a radius of 2.5 cm and an angle of 4 radians. Using the formula arc length = radius × angle, we calculate the length of arc BC as 2.5 cm × 4 radians, which equals 10 cm. Hence, the correct answer to the question is a) 10 cm.