Which sentence is punctuated correctly?
A.
Deandre's science teacher did a lot of challenging experiments; in class for example, he made his students build contraptions, for an egg drop, from two stories high.
B.
Deandre's science teacher did a lot of challenging experiments in class for example; he made his students build contraptions for an egg drop, from two stories high.
C.
Deandre's science teacher did a lot of challenging experiments in class, for example, he made his students build contraptions for an egg drop, from two stories high.
D.
Deandre's science teacher did a lot of challenging experiments in class; for example, he made his students build contraptions for an egg drop from two stories high.
