Which of the following statements is true

Options

A. The total entropy of the universe remains constant
B. The total entropy of the universe is continuously decreasing
C. The total energy of the universe is continuously decreasing
D. The total energy of the universe remains constant

Answer

To determine which of the statements is true, we need to analyze each statement based on the principles of thermodynamics.

1. **Statement 1**: The total energy of the universe remains constant.
- According to the first law of thermodynamics, energy cannot be created or destroyed, only transformed from one form to another. Therefore, the total energy of the universe does remain constant. This statement is **true**.

2. **Statement 2**: The total entropy of the universe is continuously decreasing.
- According to the second law of thermodynamics, the total entropy of the universe tends to increase over time. Therefore, this statement is **false**.

3. **Statement 3**: The total energy of the universe is continuously decreasing.
- Again, referring to the first law of thermodynamics, energy cannot be lost or destroyed, so this statement is also **false**.

4. **Statement 4**: The total entropy of the universe is always increasing.
- This is in line with the second law of thermodynamics, which states that the entropy of an isolated system will tend to increase over time. Thus, this statement is **true**.

Based on the analysis:
- The correct statements are:
- The total energy of the universe remains constant (Statement 1).
- The total entropy of the universe is always increasing (Statement 4).

However, since the question asks for which of the following statements is true, we conclude that the statement regarding the total energy of the universe remaining constant is the most straightforwardly true based on the first law of thermodynamics.

### Final Answer:
The total energy of the universe remains constant.