Table:
| September 30, | 2019 | 2018 |
| --- | --- | --- |
| Series A senior unsecured notes payable to a group of insurance companies, interest fixed at 3.35% | $  50,000 | $  50,000 |
| Series B senior unsecured notes payable to a group of insurance companies, interest fixed at 3.35% | 50,000 | 50,000 |
| Series C senior unsecured notes payable to a group of insurance companies, interest fixed at 3.70% | 25,000 | 25,000 |
| Series D senior unsecured notes payable to a group of insurance companies, interest fixed at 3.93% | 75,000 | 75,000 |
|  | 200,000 | 200,000 |
| Less unamortized debt issuance costs | (175) | (207) |
| Less current portion | (10,714) | — |
|  | $189,111 | $199,793 |
Paragraphs:
NOTE 11—FINANCING ARRANGEMENTS
Long-term debt consists of the following (in thousands):
Maturities of long-term debt for each of the five years in the period ending September 30, 2024, are as follows: 2020 — $10.7 million; 2021 — $35.7 million; 2022 — $35.7 million; 2023 — $35.7 million; 2024 — $35.7 million.
In March 2013, we entered into a note purchase and private shelf agreement pursuant to which we issued $100.0 million of senior unsecured notes, bearing interest at a rate of 3.35% and maturing on March 12, 2025. Pursuant to the agreement, on July 17, 2015, we issued an additional $25.0 million of senior unsecured notes, bearing interest at a rate of 3.70% and maturing on March 12, 2025. Interest payments on the notes issued in 2013 and 2015 are due semi-annually and principal payments are due from 2021 through 2025. On February 2, 2016 we revised the note purchase agreement and we issued an additional $75.0 million of senior unsecured notes bearing interest at 3.93% and maturing on March 12, 2026. Interest payments on these notes are due semi-annually and principal payments are due from 2020 through 2026.
The agreement pertaining to the aforementioned notes also contained a provision that the coupon rate would increase by a further 0.50% should the company’s leverage ratio exceed a certain level.
Question:
Which series of senior unsecured notes payable to a group of insurance companies is fixed at the largest interest rate?
Answer: Because 3.93%>3.70%>3.35%, the answer is: Series D.