*Question E1D05:
[97.213(d)] What must be posted at the location of a station being operated by telecommand on or within 50 kilometers of the Earth’s surface?*  

*Correct Answer is  D: All these choices are correct*  

### AI Response: (may contain errors)  

To understand the requirements for a station being operated by telecommand, let's break down the correct answer and the reasoning behind it.

### Correct Answer: D - All these choices are correct

1. **Why the correct answer is correct:**
   - According to FCC regulations, specifically 47 CFR 97.213(d), when operating a station by telecommand within 50 kilometers of the Earth's surface, certain information must be readily available at the station location. This includes:
     - A photocopy of the station license.
     - A label with the name, address, and telephone number of the station licensee.
     - A label with the name, address, and telephone number of the control operator.
   - Therefore, all the options listed (A, B, and C) are required, making D the correct choice.

2. **Why the other choices are incorrect:**
   - **A: A photocopy of the station license** - While this is a requirement, it is not the only requirement. Therefore, this choice alone is insufficient.
   - **B: A label with the name, address, and telephone number of the station licensee** - This is also a requirement, but it does not encompass all necessary information. Thus, it is not a complete answer.
   - **C: A label with the name, address, and telephone number of the control operator** - Similar to the previous choices, this is required but does not cover all the necessary information. 

### Summary
- All three pieces of information must be posted at the station location to comply with FCC regulations. Therefore, the correct answer is D, as it encompasses all the required elements.

### Key Takeaway
- Always ensure that the station location has the required documentation and contact information readily available, especially when operating by telecommand. This ensures compliance with FCC rules and facilitates communication in case of any issues.