The first question asks if the subject plays snowball in Florida in the winter. Here 'No' indicates a negative response. Thus, the sentence and by extension, the answer must also be a negative phrase. Also, snowball is a sport that requires very cold environment to play and thus,we can conclude that the subject does not play because the cold is not sufficient. Thus, the answer must contain an adjective that means 'sufficient'.
Option A is incorrect. 'isn't so cold' is a negative phrase but does not contain an adjective that means 'sufficient'. Here, 'so' is an adverb of degree. Thus, it does not convey the correct meaning
Option B is incorrect. 'its cold' is not a negative phrase. Thus, it contradicts the subject's initial response. Thus, it is incorrect
Option C is correct. 'isn't cold enough' is a negative phrase and 'enough' means 'sufficient'. Thus, the phrase indicates that the cold is not sufficient to play snowball.
Option D is incorrect. 'isn't too cold' is a negative phrase but, it does not contain an adjective that means 'sufficient'. Here, 'too' is an adverb that means 'extremely'. Thus, it is incorrect.