An isotope `._(92)U^(238)` decays successively to form `._(90)Th^(234),._(91)Pa^(234),._(92)Th^(234),._(90)Th^(230)` and `._(88)Ra^(226)`. What are the radiations emitted in these five steps?
A. `alpha, alpha, alpha,beta,beta`
B. `alpha,alpha,beta,beta,alpha`
C. `alpha,beta,beta,alpha,alpha`
D. `beta,beta,alpha,alpha,alpha`