A. Advisory Firm Description - Since 1992, SRB has provided investment management and oversight services to its parent corporation, The Plymouth Rock Company Incorporated, to property and casualty insurance companies affiliated with it, and to certain other companies. SRB is a wholly owned subsidiary of The Plymouth Rock Company Incorporated. SRB’s indirect owners with greater than 25% ownership by class of shares are Central Securities Corporation, a closed-end investment management company trading on the NYSE MKT LLC under the ticker “CET”, and James M. Stone, Chairman and Chief Executive Officer of The Plymouth Rock Company Incorporated. B. Types of Advisory Services Offered -  Investment Management I. Investment Management (SRB’s fee is inclusive of the cost of management of fixed- income securities, equity securities, and real estate.) a. Manage fixed-income securities. b. Manage equity securities and real estate.  Investment Oversight I. Investment Planning a. Develop and implement investment plan. b. Develop and implement investment guidelines and annual investment reviews. c. Review clients’ statutory investment requirements and constraints and prepare an appendix with modifications to investment guidelines where necessary. d. Conduct searches for, and selections and supervision of, fixed-income, marketable and non-marketable equity securities, and real estate. II. Performance Measurement a. Provide monthly comprehensive reports, prepare performance attribution and portfolio statistics, and assess compliance with investment guidelines. b. Prepare quarterly

investment reports for Boards of Directors. III. Custody (SRB’s fee is inclusive of the cost of custodians.) a. Conduct searches for, select, and supervise custodians. IV. Investment Accounting (SRB’s fee is inclusive of one half of the cost of Clearwater Analytics.) a. GAAP – oversee input of all investment information by Clearwater Analytics in preparation for the creation of all monthly journal entries pertaining to investments for the General Ledger. b. GAAP - prepare all monthly journal entries relating to real estate for the General Ledger. c. Statutory Accounting – review and validate NAIC Securities Valuation Office information for compilation and preparation of quarterly and annual statutory investment schedules (e.g., Schedules D, B, and BA) and Interrogatories. d. Budget – prepare and update annual forecasts for investment income. C. Customized Advisory Services – SRB tailors its investment services to conform to each client’s unique risk-and-return profile, to address each client’s investment objectives, and to comply with insurance statutes and regulations for investments where applicable. Clients may impose restrictions on investing in certain securities or types of securities. They do so by providing SRB with investment guidelines or working with SRB to develop investment guidelines embodying such restrictions. D. Wrap-Fee Programs – SRB does not offer wrap-fee programs. E. Assets Under Management – As of December 31, 2023, SRB managed $ 3,890,087,000 of assets on a discretionary basis, a substantial portion of which is managed for its affiliated companies.