4. (10 points) Four football teams, Team A, Team B, Team C, and Team D, are competing. Yangyang says: A is first, D is fourth; Xiyangyang says: D is second, C is third; Feiyangyang says: C is second, B is first. Each of their predictions is half correct, so the actual ranking from first to fourth is ( )
A. A B D C
B. A D B C
C. B A C D
D. C A B D
【Analysis】We can first assume that the first statement made by Lazy Sheep is correct, that is, A is first. Then, the statement made by Boiling Sheep that B is first is incorrect, and the statement that C is second is correct. This leads to the inference that the statement made by Happy Sheep that C is third is incorrect, and the statement that D is second is correct, which contradicts the statement that C is second. Therefore, the assumption does not hold, and we need to judge the rankings of the four based on the other statements.

【Solution】According to the analysis, assuming that the first statement made by Lazy Sheep is correct, that is, A is first, then the statement made by Boiling Sheep that B is first is incorrect,

then the statement that C is second is correct, which leads to the inference that the statement made by Happy Sheep that C is third is incorrect, and the statement that D is second is correct,
which contradicts the statement that C is second. Therefore, the assumption does not hold, so the statement made by Lazy Sheep that A is first is incorrect, and the statement that D is fourth is correct; from this, we can infer that B is first, C is third, and A is second. Therefore, the ranking is: B A C D.

Therefore, the answer is: $C$.