Which of the following is a disadvantage of renewable energy?*1 pointHigh pollutionAvailable only in few placesHigh running costUnreliable supply

The question presents several options related to the disadvantages of renewable energy sources. Let's analyze each one:

1. High pollution: This is generally not true for renewable energy sources, as they typically produce significantly lower emissions compared to fossil fuels.

2. Available only in few places: While certain renewable energy sources like geothermal or hydroelectric may be location-dependent, this doesn’t apply universally to all renewable forms such as solar and wind, which can be harnessed in many areas.

3. High running cost: Renewable energy systems may have higher initial installation costs, but their operational costs tend to be low compared to traditional energy sources.

4. Unreliable supply: This is a valid disadvantage. The availability of renewable energy can vary based on factors like weather conditions (for solar and wind), making them less reliable compared to fossil fuels which can provide a constant supply.

Conclusion

Based on the analysis, the most appropriate answer indicating a disadvantage of renewable energy is Unreliable supply.