Answer:
The correct answer out of the four given options is
option a. light elements with atomic numbers less than 5
Explanation:
Big Bang nucleosynthesis, abbreviated as BBN, also known as primordial nucleosynthesis took place after the Big Bang for about 10 s to 20 minutes and resulted in the yield of isotopes of helium-4 (), helium-3 (
) which accounts for most of the world's helium, other isotopes of hydrogen in small amounts like deuterium (D or
) and lithium isotope, lithium-7(
) in small amount.
Apart from these stable nuclei, it also yielded two radio-active isotopes: tritium() and beryllium-7(
) which due to their unstability later decayed into (
) and (
).
All of these isotopes are of light elements with atomic number less than 5.