Out of the 7 classes that I take, the proportion of A’s to B’s I got last semester was 4 to 3. Which of the following statements is false?

The ratio of the number of classes to B’s is 7 to 3.

The ratio of A’s to B’s is 4 to 3.

The ratio of A’s to the number of classes is 7 to 4.

The ratio of B’s to the number of classes is 3:7.