*Question E1A05:
[97.5] Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?*  

*Correct Answer is  C: Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation*  

### AI Response: (may contain errors)  

In this question, we are determining who is allowed to be in physical control of an amateur radio station aboard a vessel or craft that is documented or registered in the United States.

### Explanation:

1. **Correct Answer: C**  
   - **Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation**:  
     This is correct because the FCC rules allow any licensed amateur radio operator to control an amateur station. Additionally, operators authorized under reciprocal agreements (foreign operators with equivalent licenses) are also permitted to operate in the U.S. under certain conditions.

2. **Why the Other Choices are Incorrect:**
   - **Choice A: Only a person with an FCC Marine Radio license grant**  
     This is incorrect because a Marine Radio license is not required for operating an amateur radio station. The Marine Radio license pertains to maritime communications, not amateur radio operations.
   
   - **Choice B: Only a person named in an amateur station license grant**  
     This is incorrect because it limits control to only those specifically named in the license, whereas any licensed amateur operator can control the station.
   
   - **Choice D: Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit**  
     This is incorrect because an unrestricted Radiotelephone Operator Permit is not relevant to amateur radio operations. It is typically used for commercial radio operations, not amateur radio.

### Key Rule:
- **FCC Rule [97.5]**: This rule specifies who can operate an amateur station, emphasizing that any licensed amateur operator or someone authorized under reciprocal agreements can control the station.

Understanding these distinctions is crucial for ensuring compliance with FCC regulations when operating amateur radio equipment on vessels or crafts registered in the United States.