Answer: Baa3

## Explanation According to the credit rating table: **Moody's Investment Grade Ratings:** - Aaa (Highest grade) - Aa (High grade) - A (Upper medium grade) - Baa (Medium grade) - **This is the lowest investment grade category** **Moody's Speculative Grade Ratings:** - Ba (Lower medium grade) - B (Speculative) - Caa (Poor standing) - Ca (Highly speculative) - C (Lowest quality, no interest) - D (In default) With Moody's modifiers (A1, A2, A3), within the Baa category: - Baa1 is the highest tier - Baa2 is the middle tier - **Baa3 is the lowest tier** Therefore, Baa3 represents the lowest tier of investment grade credit rating by Moody's. Ba1 is already in the speculative grade category.

Author: LeetQuiz Editorial Team