All primes larger than 2 have no even digits. which is a counter example?
a) 2
b) 31
c) 67
d) 87

We can rule out a, because the question says all primers larger than 2.

Next, we can rule out b because it does not have any even digits.

Now, let's look at 67.  67 is a prime number and it does have an even digit (6).  So, c is a counter example.

D is not a counter example because it is not a prime number.