If a and b are the greatest values of `""^(2n)C_(r)and""^(2n-1)C_(r)` respectively. Then,

Options

A. a=2b
B. b-2a
C. a=b
D. none of these

Explanation

To solve the problem, we need to determine the greatest values of \( \binom{2n}{r} \) and \( \binom{2n-1}{r} \) and find the relationship between them.

### Step 1: Identify the greatest value of \( \binom{2n}{r} \)

For \( \binom{n}{r} \), the maximum value occurs at:
- \( r = \frac{n}{2} \) if \( n \) is even
- \( r = \frac{n-1}{2} \) or \( r = \frac{n+1}{2} \) if \( n \) is odd

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