Both roots of the quadratic equation $ x^2 \minus{} 63x \plus{} k \equal{} 0$ are prime numbers. The number of possible values of $ k$ is

$ \textbf{(A)}\ 0 \qquad \textbf{(B)}\ 1 \qquad \textbf{(C)}\ 2 \qquad \textbf{(D)}\ 3 \qquad \textbf{(E)}\ \textbf{more than four}$
1. **Identify the roots using Vieta's formulas:**
   By Vieta's formulas, for the quadratic equation \(x^2 - 63x + k = 0\), the sum of the roots \(a\) and \(b\) is given by:
   \[
   a + b = 63
   \]
   and the product of the roots is:
   \[
   ab = k
   \]

2. **Determine the nature of the roots:**
   Since both \(a\) and \(b\) are prime numbers, we need to find pairs of prime numbers that add up to 63.

3. **Check the parity of the sum:**
   The sum of two primes is usually even (since the sum of two odd numbers is even), but 63 is odd. Therefore, one of the primes must be 2 (the only even prime), and the other must be an odd prime.

4. **Find the pairs:**
   Let \(a = 2\). Then:
   \[
   b = 63 - 2 = 61
   \]
   Check if 61 is a prime number. Indeed, 61 is a prime number.

5. **Verify the product:**
   Using Vieta's formulas again, the product of the roots \(a\) and \(b\) is:
   \[
   ab = 2 \cdot 61 = 122
   \]
   Therefore, \(k = 122\).

6. **Check for other pairs:**
   Since 2 is the only even prime number, and we have already found the pair \((2, 61)\), there are no other pairs of prime numbers that add up to 63.

Conclusion:
There is only one possible value for \(k\), which is 122.

The final answer is \(\boxed{1}\)