B

Step 1: Understand the principle of a ballistic galvanometer. A ballistic galvanometer is an instrument used to measure the total charge that flows through the coil when a current is briefly passed through it.

Step 2: Identify the materials used in the construction of the galvanometer. The coil is wound on a non-metallic frame to minimize certain effects during its operation.

Step 3: Recognize the effects of metallic frames. If a metallic frame were used, changing magnetic fields would induce circulating currents within the frame itself, called eddy currents. These currents can create magnetic fields that oppose the motion of the coil, leading to inaccuracies in measurement and damping the galvanometer's response.

Step 4: Conclude that using a non-metallic frame avoids the production of eddy currents. This design choice is to enhance the performance and precision of the ballistic galvanometer.

Therefore, the correct answer is Option B: Avoid the production of eddy currents.