The gene only recently evolved in humans. The technology used to study genes is still being developed. Scientists were not interested in genes until a few years ago. Scientists were sure they had already discovered every possible gene.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Researchers recently discovered a gene in humans that previously was unknown to science. Which statement best explains why the gene probably was not discovered much sooner?
Possibilities:
- The gene only recently evolved in humans.
- The technology used to study genes is still being developed.
- Scientists were not interested in genes until a few years ago.
- Scientists were sure they had already discovered every possible gene.

The technology used to study genes is still being developed.