Number of biosphere reserves in our country is:
(23,13,27,17)

Explanation

To determine the number of biosphere reserves in our country, we can follow these steps:

1. **Understand the Concept of Biosphere Reserves**: Biosphere reserves are designated areas aimed at conserving biodiversity and promoting sustainable use of natural resources. They consist of three zones: the core area (no human interference), the buffer area (limited human activity), and the transition area (sustainable resource use).

2. **Identify the Options Given**: The options provided are 23, 13, 27, and 17.

3. **Recall the Information**: From the study material or previous knowledge, we need to recall how many biosphere reserves are present in our country.

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