I'll post the question again, so it's easier to see.

To begin, we know that #cows + #pigs = 40
The important thing to note is that statement (1) reads "...there are more than twice as many cows as there are pigs"
The "more than" makes this info INSUFFICIENT

(2) is clearly not enough into (INSUFFICIENT)

(1+2) There are 13 or more pigs. If there are 13 pigs, then there must be more than 26 cows (27, 28, 29, etc). However, since the pigs and cows must sum to 40, there must be 27 cows (if there are 13 pigs)
But, perhaps there are 14 pigs or more. We better examine this.
If there are 14 pigs, then there must be more than 28 cows. We can see that if there are more than 28 cows, our entire pig/cow population will exceed 40. In fact, if there are more than 13 pigs, it's impossible to have them cows and pigs sum to 40 (and retain statement (1))
So, there must be exactly 13 pigs and 27 cows. So, (1+2) is SUFFICIENT.
Choose C.