The correct answer is C. Hydrogen
Step-by-step explanation:
The Solar Nebular Disk Model (SNDM) is the model about the formation and evolution of solar systems that is more widely accepted nowadays. In this model that was first proposed in the XVIII century, stars begin as the result of massive molecular clouds that are mainly composed of Hydrogen as these clouds are unstable and then through a complex chemical process become regular stars. Also, in this model, it is believed the formation of stars is linked to the formations of planets and other astronomical bodies that led to complete solar systems, which implies stars and other elements form based on nebula material. Therefore, according to the solar nebular disk model stars from in massive dense cloud full of Hydrogen.