Final answer:
Force F2 could be the second force.
Step-by-step explanation:
Based on the information provided, force F2 could be the second force. According to the equation F2 = I21B₁, it is mentioned that F2 is equal to a constant multiplied by B₁. Since F2 is the second force, the options that could be the second force are F1, F2, F3, and F4. Therefore, the correct answer is B) F2. In general terms, if we are discussing Newton's Third Law, we would say that the second force would have the same magnitude but the opposite direction as the first force. However, without a clearer understanding of what the forces represent (e.g., gravitational, electromagnetic), or the context in which they are acting, providing an accurate and confidently correct answer is not feasible. Further clarification of the problem or additional details would be needed to identify the second force accurately.