听力原文：Hello, Mark. This is Sam Rogers. I'm calling to let you know I agree with the ter

听力原文： Hello, Mark. This is Sam Rogers. I'm calling to let you know I agree with the terms of the contract you sent. I signed it and sent it via overnight courier this afternoon, so you should receive it sometime tomorrow. I'm going to get started on the project immediately, and I'm looking forward to working with you on it. I also wanted to let you know that I'll be in San Francisco from March 2nd through March 8th on unrelated business. But I'd like to get together with you while I'm there to talk about the project, and show you what I'll have completed by then. Let me know if you'll have time during that week to see me. Give me a call back at 312-274-5555 when you have a chance. Thanks.

What does the speaker tell Mark he has done？

A．Sent a signed contract

B．Made copies of the contract

C．Changed the terms of a contract

D．Given the contract to his lawyer