------
## 最终结论
```python
def index_minimum(records):
    min_value = float('inf')
    min_index = -1
    
    for index, (name, value) in enumerate(records):
        if value < min_value:
            min_value = value
            min_index = index
            
    return records[min_index][0]

# Test cases
assert index_minimum([('Rash', 143), ('Manjeet', 200), ('Varsha', 100)]) == 'Varsha'
assert index_minimum([('Yash', 185), ('Dawood', 125), ('Sanya', 175)]) == 'Dawood'
assert index_minimum([('Sai', 345), ('Salman', 145), ('Ayesha', 96)]) == 'Ayesha'
```