A person is guilty of criminal sale of a controlled substance in the fourth degree when he knowingly and unlawfully sells:

1. a narcotic preparation; or

2. a dangerous depressant or a depressant and the dangerous depressant weighs ten ounces or more, or the depressant weighs two pounds or more; or

3. concentrated cannabis as defined in paragraph (a) of subdivision four of section thirty-three hundred two of the public health law; or

4. phencyclidine and the phencyclidine weighs fifty milligrams or more; or

5. methadone; or

6. any amount of phencyclidine and has previously been convicted of an offense defined in this article or the attempt or conspiracy to commit any such offense; or

6-a. ketamine and said ketamine weighs four thousand milligrams or more.

7. a controlled substance in violation of section 220.31 of this article, when such sale takes place upon school grounds or on a school bus; or

8. a controlled substance in violation of section 220.31 of this article, when such sale takes place upon the grounds of a child day care or educational facility under circumstances evincing knowledge by the defendant that such sale is taking place upon such grounds. As used in this subdivision, the phrase "the grounds of a child day care or educational facility" shall have the same meaning as provided for in subdivision five of section 220.44 of this article. For the purposes of this subdivision, a rebuttable presumption shall be established that a person has knowledge that they are within the grounds of a child day care or educational facility when notice is conspicuously posted of the presence or proximity of such facility; or

9. one or more preparations, compounds, mixtures or substances containing gamma hydroxybutyric acid, as defined in paragraph four of subdivision (e) of schedule I of section thirty-three hundred six of the public health law, and said preparations, compounds, mixtures or substances are of an aggregate weight of twenty-eight grams or more.

Criminal sale of a controlled substance in the fourth degree is a class C felony.