The correct ste of carbonate ores is
(a) Magnesite (b) Siderite (c) Zincite (d) Argentite

Options

A. a,b
B. a,d
C. c,d
D. b,c

Explanation

To determine the correct set of carbonate ores from the given options, we need to analyze each option based on their chemical composition:

1. **Magnesite (MgCO3)**:
- Magnesite is a carbonate mineral with the formula MgCO3. Since it contains the carbonate group (CO3), it is classified as a carbonate ore.

2. **Siderite (FeCO3)**:
- Siderite is another carbonate mineral with the formula FeCO3. Similar to magnesite, it also contains the carbonate group (CO3), making it a carbonate ore as well.

3. **Zincite (ZnO)**:
- Zincite is the mineral form of zinc oxide, with the formula ZnO. It does not contain the carbonate group (CO3), so it is not classified as a carbonate ore.

4. **Argentite (Ag2S)**:
- Argentite is the main ore of silver, with the formula Ag2S. This compound is a sulfide ore, not a carbonate ore, as it lacks the carbonate group.

Based on the analysis:
- The correct carbonate ores from the options provided are **Magnesite (MgCO3)** and **Siderite (FeCO3)**.
- Therefore, the correct answer is **(a) Magnesite and (b) Siderite**.

Final Answer: The correct set of carbonate ores is (a) Magnesite and (b) Siderite.