Search for grammatical errors in the underlined sections of the following sentences and select the option that best corrects them. If there is no error, choose option A.

The first part of the test was on chemistry, the second on mathematics, and the third on english.
on mathematics, and the third on english.
on mathematics; and the third on English.
on Mathematics; and the third on English.
on mathematics, and the third on English.
on mathematics: and the third on English.