The correct answer is absence of jaws.
Lampreys and hagfish are in the class Agnatha, they are jaw-less fish. The members of the agantha class are probably the earliest vertebrates. Scientists have found fossils of agnathan species from the late Cambrian period that occurred 500 million years ago.
There are four main organelles:
Nucleus
Ribosome
Rough Endoplasmic Reticulum
Golgi Apparatus
However, the ribosome is the most responsible for making protein, even though the other 3 are also important. It isn't a cell organelle but a cell structure that produces proteins.
The correct answer would be A
