Answer:
2
Step-by-step explanation:
One of them has to be 2. Two odd numbers added together make an even number. So you have two pairs of odd prime numbers and 2 must be the last one. If it is not then the sum will be odd.
Here's an example
3 + 5 + 7 + 11 = 26 which is even. If the next prime is odd, the whole sum will be odd.
26 + 17 = 43
However if the 5th number is two, then the sum of the 5 primes will be even.
26 + 2 = 28