Strongest Oxidizing Agent: d) ReO ^(1-)

Explanation:

1. Introduction:
In order to determine the strongest oxidizing agent among the given options, we need to consider their reduction potentials. The higher the reduction potential, the stronger the oxidizing agent.

2. Reduction Potentials:
The reduction potentials of the given species are as follows:

- WO ^(2-): -1.23 V
- CrO ^(2-): -0.13 V
- MoO ^(2-): -0.45 V
- ReO ^(1-): +0.57 V

3. Analysis:
Based on the reduction potentials, we can see that the ReO ^(1-) ion has the highest reduction potential (+0.57 V) among the given species. This indicates that ReO ^(1-) is the strongest oxidizing agent.

4. Explanation:
The reduction potential is a measure of the tendency of a species to gain electrons and get reduced. A higher reduction potential means that the species has a greater tendency to gain electrons and get reduced, indicating that it is a strong oxidizing agent.

In this case, the ReO ^(1-) ion has the highest reduction potential, indicating that it has a greater tendency to gain electrons and get reduced compared to the other species. Therefore, ReO ^(1-) is the strongest oxidizing agent among the given options.

5. Conclusion:
The strongest oxidizing agent among the given options is d) ReO ^(1-).