The foremost advantage of bipedal locomotion is

Options

A. To increase in rate of locomotion
B. To provide more support to body
C. The reduction in body weight
D. To spare the fore limbs for other jobs

Answer

### Step-by-Step Solution

1. **Understanding Bipedal Locomotion**:
- Bipedal locomotion refers to the ability to move using two legs. This is a characteristic feature of humans and some birds.

2. **Identifying Advantages**:
- The question asks for the foremost advantage of bipedal locomotion. We need to evaluate the potential benefits associated with this form of movement.

3. **Evaluating Common Advantages**:
- **Increased Rate of Locomotion**: Initially, one might think that bipedal locomotion increases speed. However, it has been noted that in birds, the rate of locomotion does not necessarily increase.
- **Support for the Body**: Another consideration is whether bipedal movement provides better support. However, it does not significantly aid in walking or running.
- **Reduction in Body Weight**: This is a crucial point. Bipedal locomotion allows for a reduction in body weight, particularly in birds, where their legs are adapted to be thin and lightweight to facilitate flight.
- **Sparing the Forelimbs**: While bipedal locomotion may allow forelimbs to be used for other purposes, in birds, the forelimbs are adapted for flight, which does not support this advantage.

4. **Conclusion**:
- After evaluating the potential advantages, the foremost advantage of bipedal locomotion is the **reduction in body weight**. This adaptation is particularly evident in birds, where lightweight legs aid in their ability to fly.

### Final Answer
The foremost advantage of bipedal locomotion is the reduction in body weight.

---