A thorium-232 nucleus decays by a series of α and β-emissions until it becomes lead-208. How many α emissions and how many β emissions occur in this series?
A) 4 α emissions, 6 β⁻ emissions
B) 6 α emissions, 4 β⁻ emissions
C) 6 α emissions, 12 β⁻ emissions
D) 12 α emissions, 6 β⁻ emissions
E) 12 α emissions, 24 β⁻ emissions