A man standing on a platform holds weights in his outstretched arms. The system is rotated about a central vertical axis. If the man now pulls the weights inwards close to his body then

Options

A. the angular velocity of the system will increase
B. the angular momentum of the system will remain constant
C. the kinetic energy of the system will increase
D. all of the above

Explanation

To solve the problem, we need to analyze the situation using the principles of rotational mechanics, particularly focusing on angular momentum and angular velocity.

### Step-by-Step Solution:

1. **Understanding the System**:
- We have a man standing on a platform holding weights in his outstretched arms. The entire system (man + weights) is rotating about a central vertical axis.

2. **Initial Condition**:
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