Assertion : One atomic mass unit (amu) is mass of an atom equal to exactly one-twelfth of the mass of a carbon-12 atom.
Reason : Carbon-12 isotope was selected as standard.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false.

Answer

A

Explanation

For universally accepted atomic mass unit in 1961, `C-12` was selected as standard. However the new symbol used is 'u' (unified mass) in place of amu.