In the 1800s lord kelvin estimated the age of the earth, utilizing a number of assumptions.
which wrong assumption was the primary reason why his estimate (approximately 20 million years) was so wildly inaccurate?

a. that the earth was once hotter than it presently is today
b. that the earth may have been molten when first formed
c. that no new heat has been added to the earth since its initial formation
d. that the earth would lose heat over time through radiation into outer space

B. that the Earth may have been molten when first formed

Explanation:

In 1800 the lord kelvin estimated the age of the earth and it provides to be about 100 million years and was made in appreciation of the scientific discoveries.  And he calculated this to the age of the earth with the help of the thermal gradients ad realized that the earth mantel was converting and he invalidated its estimates.  And has initially accepted the earth age to be 100 million as old as e believed that the geologic process can complete their word within a time frameworks and the 20 years was insufficient.