Final answer:
RNA is thought to be the genetic material in the first organisms due to its ability to store information and catalyze reactions, as suggested by the RNA World Hypothesis. The correct option is a).
Step-by-step explanation:
It is now thought that RNA was the genetic material in the first living organisms on Earth.
This idea is supported by the RNA World Hypothesis, which suggests that RNA may have been the first organic molecule to evolve due to its ability to encode genetic instructions and carry out chemical reactions, functions that are performed by DNA and proteins respectively in current life forms.
The hypothesis addresses the 'chicken-and-egg' problem of which molecule, DNA or proteins, came first by proposing a scenario where RNA served both roles before the evolution of DNA and proteins.
RNA's dual ability to catalyze biological reactions and store genetic information makes it a prime candidate as the original molecule of life. It aligns with the requirements of prebiotic chemistry for a molecule that could self-replicate and catalyze other chemical reactions, potentially leading to the complexity of life.
Despite the increasing acceptance of the RNA world hypothesis, a great deal remains to be discovered about life's origins. Option a) is the correct one.