`Y-`shaped energy flow model was given by

Options

A. `H.T.`Odum
B. `E.P.`Odum
C. Tansley
D. Both `(a)` and `(b)`

Answer

To answer the question regarding who proposed the Y-shaped energy flow model, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Model**: The Y-shaped energy flow model is a concept in ecology that illustrates how energy flows through different food chains in an ecosystem.

2. **Recognize the Contributors**: The question provides four options: H.T. Odom, E.P. Odom, Densley, or both H.T. Odom and E.P. Odom.

3. **Historical Context**: H.T. Odom pioneered the Y-shaped energy flow model in 1956. This model emphasizes the interaction between two food chains: the grazing food chain and the detritus food chain.

4. **Further Development**: E.P. Odom, in 1983, contributed to this field by creating a generalized model that combined the Y-shaped model with the single channel model. This combination is applicable to both terrestrial and aquatic ecosystems.

5. **Conclusion**: Since both H.T. Odom and E.P. Odom made significant contributions to the understanding and development of the Y-shaped energy flow model, the correct answer is that both A (H.T. Odom) and B (E.P. Odom) are correct.

### Final Answer:
The Y-shaped energy flow model was given by both H.T. Odom and E.P. Odom.

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